Dishwasher Replacement Calculator

This calculator weighs keeping your dishwasher against replacing it. Describe the old unit by picking its model from the ENERGY STAR lists, by the year it was made, or from the energy figure on its EnergyGuide label and the water use in its specification sheet. Then pick the new model and enter how many loads you run a week and what you pay for electricity, gas and water. It works out each unit's yearly energy and water use and cost, the yearly saving, the net cost of the new unit, the simple and discounted payback, and the cost over the years you choose of keeping the old unit, replacing it now, or replacing it when it wears out.

Model figures come from federal sources only: the ENERGY STAR certified and historical lists published by the EPA, and the DOE test procedure, efficiency standards and technical support document. Default utility prices come from the EIA and EPA WaterSense. You set the price of the new unit; the opening example uses an illustrative one.

Purpose and model boundary

This calculator compares two ways forward for a household dishwasher: keep the unit you have, or replace it with a new one. It reduces each unit to the energy and water it uses per load, scales that to the number of loads you run, prices it at your electricity, gas and water rates, and sets the yearly saving against what the new unit costs installed. Over the number of years you choose, it compares keeping the old unit, replacing it now and, when you say how many years the old unit has left, replacing it when it wears out.

Every figure on this page is computed by the spreadsheet; the page adds nothing to it. The model covers running cost and purchase cost only. It does not judge cleaning or drying performance, noise, capacity or reliability, and it does not price financing, warranties or the time value of your own labour.

Inputs and units

• The old dishwasher, described in one of four ways:
  • a model from the ENERGY STAR historical lists (models certified from 2004 to 2022);
  • a model from the current ENERGY STAR list, for a unit that is still certified;
  • the year it was made, when the model is not listed, with the basis for that year: typical use from DOE studies, or the federal maximum allowed; optionally your own water use per load;
  • manual entry: the yearly energy figure from its EnergyGuide label and the label's test basis (the current DOE basis, Appendix C1; a number of cycles a year stated on the label; or Unknown), and the water used per load from the product's specification sheet or manual.
• Type: Standard or Compact, for each unit. For a listed model, choose the type first, then pick the model from that type's list. Each entry reads "Brand | Model number". Model numbers are given exactly as ENERGY STAR lists them, including the * characters that stand for any character and the # characters that stand for a digit, which together cover a family of model numbers sold under one listing: your unit's full model number need not match character for character.
• The new dishwasher: a model from the current ENERGY STAR list, or manual entry as for the old unit, and its price, more than $0 and at most $20,000. The price is always yours to set (see "Worked examples and prices").
• Use: loads a week, 0 to 50.
• Utility prices, each optional: the state, which sets the default electricity price; your own electricity price in dollars per kWh; the fuel of your water heater (electric or gas) and your own gas price in dollars per therm; your own combined water and sewer price in dollars per 1,000 gallons. A blank price uses the default described under "Data and vintage".
• Purchase and upkeep: installation, removal and disposal of the old unit, sales tax on the price, verified rebates, the sale or scrap value of the old unit, and yearly upkeep for each unit. Each is optional and counts as zero when left blank.
• The comparison: the years to compare (1 to 30), the yearly change in utility prices, the discount rate, and, optionally, the years the old unit has left, the expected life of the new unit, and the standby power of either unit in watts.

Energy is in kWh, gas in therms, water in US gallons and money in dollars.

Governing relationships

The label basis. An ENERGY STAR or EnergyGuide figure for a dishwasher is a yearly energy use under the DOE test procedure. Current figures (Appendix C1, and Appendix C for listings before 2013) assume 215 loads a year; an older label may not, so for a manual entry choose its basis, or Unknown. The calculator divides the label's yearly kWh by its cycles a year to get the energy per load, then multiplies by your loads: loads a week times 52. With the basis Unknown, the label figure is used as it stands, without scaling to your loads, and the status says so.

Standby. A label figure already includes the energy to heat the water the machine takes in and its standby energy. If you enter a standby wattage, that standby is taken out of the label figure and counted as a fixed yearly amount that does not change with your loads; nothing is added on top.

Water heating. With an electric water heater the per-load figure is used as it stands. With a gas water heater, the hot-water share is moved from electricity to gas using the test procedure's own constants: a 70 °F temperature rise (for the usual 120 °F inlet), 0.0024 kWh or 8.2 Btu per gallon per °F, and a gas water heater recovery efficiency of 0.75. The machine's own electricity per load is the per-load label figure, less any standby, less water per load × 70 × 0.0024 kWh, floored at zero; its gas per load is water per load × 70 × 8.2 ÷ 0.75 ÷ 100,000 therms.

A unit described by the year it was made.

• The typical figure is the DOE's average energy per cycle of new dishwashers shipped that year, all sizes combined, applied to standard units made 1990 to 2018, times 215. DOE does not say whether it includes standby; the calculator treats it as excluded, so a standby wattage you enter is added on top.
• The federal maximum is the most energy, and from 2010 the most water, a unit made that year was allowed to use under 10 CFR 430.32(f). It exists for standard and compact units made 1995 to 2022. Before 2010 it is derived as 215 ÷ the minimum energy factor, 467.4 kWh a year for a standard unit and 346.8 for a compact one, and excludes standby, so a standby wattage you enter is added on top. From 2010 the limit includes standby, so a wattage you enter is taken out of it.
• When the basis you ask for does not exist for that type and year, the other one is used and the status says so.
• No DOE typical water figure was found, so water comes from your own figure when you enter one, and otherwise from the federal maximum for that year. Before 2010 there was no federal water limit, and you enter the water use yourself.

Yearly cost. For each unit, the yearly utility cost is its kWh times the electricity price, plus its therms times the gas price, plus its gallons times the water and sewer price ÷ 1,000. Adding yearly upkeep gives its yearly cost, and the yearly saving is the old unit's yearly cost less the new unit's.

Purchase cost. The capital cost is the price × (1 + sales tax rate) + installation − rebates. The net initial cost adds removal and disposal and takes off the old unit's sale value.

Payback. Simple payback is the net initial cost ÷ the first year's saving, when the saving is positive; otherwise there is no payback. Discounted payback is the first year in which the cumulative discounted net benefit of replacing now reaches zero within the years compared.

The three paths over the years compared. Utility prices change each year by the rate you enter; upkeep stays flat; costs fall at the end of each year and are discounted at your rate.

• Keep: the old unit's yearly cost every year.
• Replace now: the net initial cost today, then the new unit's yearly cost, less the value left in the new unit at the end.
• Replace at end of life (when you enter the years the old unit has left and they are fewer than the years compared): the old unit's yearly cost until it fails, then the capital cost and disposal in that year at today's price (no sale value, because the unit has failed), then the new unit's yearly cost, less the value left in the new unit at the end.

If you enter the new unit's expected life, the value left in it at the end is its capital cost × the share of that life still remaining, on a straight line; left blank, no value is counted. The net present value of replacing now is the present cost of keeping less the present cost of replacing now: positive means replacing now costs less.

Calculation sequence

The spreadsheet first finds each unit's label figure, water use and test basis from the list, the year table or your entries, and checks the inputs. It then reduces each unit to its standby energy, energy per load, gas per load and water per load, and from those computes the yearly quantities, the yearly costs and the saving. The purchase cost, the paybacks, the present values of the three paths and the year-by-year cash flow follow. The sensitivity table uses the same per-load figures, so it cannot disagree with the main result. A block of consistency checks, including that the discounted cash flow reaches the same net present value as the closed-form formula and that the label figure is reproduced exactly under its own test basis, runs before the status is returned.

Outputs and interpretation

The headline is the yearly saving from replacing the old unit, with the simple payback and the net present value of replacing now. For each unit the results give its label figure, its energy per load (blank when the label basis is unknown), its yearly kWh, therms and gallons, and its yearly energy, water and total cost, with the electricity, gas, water and sewer prices actually used and a note on where each came from. The decision results give the net initial cost, the discounted payback year, the total and present cost of keeping, of replacing now and of replacing at end of life, and a plain verdict on replacing now and on replacing at end of life.

The cash-flow table shows each year from 0 to the years compared: the cost of each path, the net benefit of replacing now, and its cumulative, discounted and cumulative discounted values. The sensitivity table shows the yearly saving at 1 to 7, 10 and 14 loads a week, and at 0.5, 0.75, 1, 1.25 and 1.5 times the electricity price used.

A model card beside each pick shows the model's type, the year it was listed or became available, its label energy and water use and the list it came from.

The first chart, “Cumulative net benefit of replacing now, by year”, shows Undiscounted and Discounted by year. The second chart, “Cost over the years compared”, shows Total and Present value by option. The third chart, “Running cost in year 1”, shows Energy, Water and sewer and Upkeep by unit, stacked.

Validation and status logic

The workbook returns one status, chosen in this order: NOT VALID, then CHECK, then OK.

• NOT VALID names the first problem: a source that is not one of its options; a listed model that is not in its list, or whose type differs from the type chosen; no year made, or no figure on either basis for that type and year; a manual label figure missing or not above 0 and at most 2,000 kWh a year; a manual label basis that is not one of its options; stated label cycles missing or outside 50 to 600; a water figure missing or outside 0 to 20 gallons per load, including a unit made before 2010 with no water figure; a standby or upkeep figure outside its range; loads a week outside 0 to 50; no electricity price, or your own price outside $0.01 to $2.00 per kWh; a water-heating choice that is not one of its options, or your own gas price outside $0.10 to $10.00 per therm; your own water and sewer price outside 0 to $100 per 1,000 gallons; a price for the new unit that is missing, not above $0 or above $20,000; another money or rate input outside its range; or years to compare, years left or expected life that are not whole numbers in range. NOT VALID is a refusal, not a numeric answer: the page withholds calculated figures.
• CHECK accompanies a computed result that needs the stated review: the requested year-made basis does not exist for that year, so the other was used; a typical energy figure paired with the federal maximum water use, so your unit may use less water; the federal maximum basis used, so your unit may use less and the saving may be overstated; a manual label whose basis is unknown, so the label figure is used without scaling to your loads; label energy and water figures that leave negative machine energy under the test basis; old and new units of different types (standard and compact); zero loads a week; a new unit that does not cost less to run than the old one at your use, so there is no payback; or an old unit with fewer years left than the years compared, so the end-of-life path is the realistic one.
• OK otherwise.

Assumptions and limitations

• The historical lists are three snapshots. They hold the models certified under ENERGY STAR specification versions 4.1, 5.2 and 6.0, as archived; models certified and withdrawn between those snapshots are missing. Every listed model met ENERGY STAR when it was certified, so if you pick a listed model to stand in for a different unit, it probably used less energy than a typical unit of its age, and the saving may be understated. A unit that is not listed is better described by the year it was made.
• Typical figures are by year shipped, all sizes combined. They come from the DOE's 2022 preliminary technical support document, which shows no shipment-weighted data after 2014 although its table runs to 2018. DOE does not state whether those figures include standby. This model treats standby as excluded and adds it separately; that is a modelling assumption.
• The federal maximum is a ceiling, not a measurement. A unit described on that basis may use less, so the saving may be overstated.
• 215 loads a year is the label's basis, not your use. Your use enters only through loads a week.
• Default utility prices are averages. The default electricity price is the EIA's annual average residential price for the state, not your tariff; the gas price is the EIA's US average residential price; the water and sewer price is a national average estimate published by EPA WaterSense. Enter your own prices from your bills for a better answer.
• One price change rate applies to electricity, gas and water alike. The future purchase in the end-of-life path is priced at today's price.
• There is no loan, no depreciation other than the value left in the new unit at the end, and no resale other than the old unit's sale value when it is replaced now.

Data and vintage

The model lists, the year table and the default prices are reviewed reference tables inside the workbook, refreshed from their federal publishers; their version is shown in the result details.

• Current models: 700 dishwashers from the ENERGY STAR certified residential dishwashers dataset (EPA), US market, downloaded 2026-10-28. Where a model is listed more than once, the most recent listing is used. One listing whose model number the published file carries with an unreadable character is left out; describe that unit by manual entry.
• Historical models: 1,701 dishwashers from the ENERGY STAR historical lists (specification versions 4.1, 5.2 and 6.0), certified from 2004 to 2022, downloaded 2026-10-28, without models still on the current list.
• Year made: the federal maximum energy and water use by year of manufacture from 10 CFR 430.32(f), for standard and compact units made 1995 to 2022, and the DOE's typical energy use for standard units made 1990 to 2018 from the January 2022 preliminary technical support document.
• Default utility prices: EIA 2025 annual average residential electricity prices by state (Form EIA-861), the EIA 2025 US average residential natural gas price ($15.34 per thousand cubic feet, or $1.4807 per therm at 1,036 Btu per cubic foot), and EPA WaterSense's 2024 estimate of the national average water and sewer price ($16.83 per 1,000 gallons).

Worked examples and prices

Prices are not part of the reference data: the price of the new unit is an input you set. The opening example and the five worked examples each use an illustrative price for the new unit, so that the example computes, and each says so: “Illustrative price for this example, not a quote or a current price. Prices vary: check current prices online or enter your own.”

Restrictions and non-computing states

The calculator enforces its numeric and choice limits before it accepts a result. A model that is not in its list or does not match the type chosen, a manual unit with no label energy, a unit with no water figure where one is needed and a missing price for the new unit are refused by the workbook.

Errors and warnings

A request rejected by the page's input limits is not a computed result. A transport or service failure, a timeout or a cancelled run cannot establish a fresh workbook answer, and the last result stays on the page marked as out of date. Check your unit's EnergyGuide label and your own bills before relying on a result for a purchase.

Sources and further reading

The calculator reads its model lists, its year-made figures and its default utility prices from reviewed reference tables inside the workbook, by record, with their version shown in the result details. Every table comes from a US federal source. The sources below publish the data and the rules the model applies. They do not endorse this calculator.

• ENERGY STAR Certified Residential Dishwashers (EPA) lists currently certified dishwashers with their yearly energy use and water use per cycle, and states the 215-cycle basis of the yearly figure (retrieved 2026-10-28).
• ENERGY STAR, Dishwashers: information for partners (EPA) links the historical lists of dishwashers certified under earlier specifications, versions 4.1, 5.2 and 6.0 (retrieved 2026-10-28).
• DOE test procedure for dishwashers, 10 CFR 430 Subpart B, Appendix C1 (CFR 2019 edition, govinfo) defines the yearly energy figure on 215 cycles a year, as Appendix C did for earlier listings, and the water-heating constants: a 70 °F temperature rise for the usual 120 °F inlet, 0.0024 kWh and 8.2 Btu per gallon per °F, and a 0.75 gas water heater recovery efficiency (retrieved 2026-10-28).
• DOE energy conservation standards, 10 CFR 430.32 (eCFR) sets the current federal maximum energy and water use for dishwashers (retrieved 2026-10-28).
• 10 CFR 430.32 (CFR 2012 edition, govinfo) holds the minimum energy factors for dishwashers made from 1994 and the energy and water limits for those made from 2010, the basis of the federal maximum by year made before 2013 (retrieved 2026-10-28).
• DOE, Consumer dishwashers preliminary technical support document, January 2022, whose Table 3.10.1 gives the average energy per cycle of new dishwashers shipped each year, all sizes combined, the basis of the typical figure by year made; the table does not say whether standby is included, and the calculator treats it as excluded (retrieved 2026-10-28).
• EIA, Detailed state data (Form EIA-861) gives the average residential electricity price by state, used here for 2025 (retrieved 2026-10-28).
• EIA, Natural gas prices gives the US average residential price, $15.34 per thousand cubic feet for 2025, and EIA, Heat content of natural gas delivered to consumers the 1,036 Btu per cubic foot used to convert it to $1.4807 per therm (retrieved 2026-10-28).
• EPA WaterSense, Data and information used by WaterSense estimates the 2024 national average residential water price at $7.74 and wastewater price at $9.09 per 1,000 gallons, $16.83 in all, used here as an editable default (retrieved 2026-10-28).

This is an educational estimate of running and purchase costs for the units and prices you enter, not a product recommendation or a quote. The ENERGY STAR lists show each model's rated use under the test procedure, not your unit's measured use; check your unit's EnergyGuide label and your own bills before acting on a result.