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finance-business · personal-finance · retirement-income

Required Minimum Distribution Calculator

Projects the required minimum distributions from a retirement account year by year from a life-expectancy divisor that falls as you age, and reports the largest single year, the total distributed and the balance left at the end. Enter a tax rate and it also reports the tax on the distributions. The divisors are illustrative inputs you take from the governing table yourself; none is reproduced here.

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Calculator overview

Inputs and outputs

This summary comes from the calculator's published input and output contract.

Inputs

Account Balance (required)
About this input

The balance the distribution is calculated on, which for a real distribution is the prior year-end value of the account.

Unit currency Default 800000 Range At least 0
Annual Divisor Decrease (required)
About this input

How much the divisor falls each year. Through the seventies and eighties it is close to nine tenths of a year annually; check it against the table for the ages you are projecting.

Unit years Default 0.9 Range 0 to 5
Expected Return (required)
About this input

The average annual return on what remains in the account after each distribution.

Unit fraction Default 0.05 Range 0 to 0.25
First Divisor (required)
About this input

The life-expectancy divisor for your first distribution year, taken from the governing table for your age and circumstances. ILLUSTRATIVE: no table is reproduced here, and a wrong divisor gives a confidently wrong answer.

Unit years Default 26.5 Range 1 to 60
Starting Age (required)
About this input

The age at which required distributions begin for you. Used to label the schedule and the charts.

Unit years Default 73 Range 60 to 100
Tax Rate On Distributions
When omitted Blank
About this input

Optional. A flat rate applied to the distributions to show what you would keep. Leave it blank and the two tax outputs stay blank; distributions are reported before tax.

Unit fraction Default Not set Range 0 to 0.6
Years To Project (required)
About this input

How many years of distributions to project.

Unit years Default 20 Range 1 to 50

Outputs

Age Of Largest
About this output

Your age in that year.

Unit years
Ending Balance
About this output

What is left in the account at the end of the period.

Unit currency
Final Divisor
About this output

The divisor in the last year projected, after the annual falls, floored at one.

Unit years
Final Year Percentage
About this output

The required percentage in the last year projected. Comparing it with the first-year percentage is the point of the second chart: the percentage rises every year.

No unit declared
First Year Distribution
About this output

What you are required to withdraw in the first year.

Unit currency/yr
First Year Percentage
About this output

That distribution as a percentage of the balance, which is simply one divided by the divisor.

No unit declared
Largest Distribution
About this output

The biggest single-year distribution over the period. It usually falls well after the first year, because the rising required share outruns the falling balance for a while.

Unit currency/yr
Model Status
About this output

Reads OK, or explains why the inputs are not valid or why the answer deserves a second look.

No unit declared
Total After Tax
About this output

What you would keep from the distributions after that tax. Blank until you supply a rate.

Unit currency
Total Distributed
About this output

Everything required to be withdrawn across the whole projection, before tax.

Unit currency
Total Tax On Distributions
About this output

Tax on the distributions at the flat rate you supplied. Blank until you supply one.

Unit currency
This page is provided by LogicCommons for informational purposes only. Results are model outputs computed from the inputs you supply and are not financial, investment, tax, accounting, or legal advice, and no advisory relationship is created. Verify all inputs and results independently before relying on them in any decision.

LogicCommons is in beta. If a result, label, or reference looks wrong, tell us here; we read every message.

Methodology

Purpose and model boundary

Use this calculator to project annual required withdrawals from a retirement account using a starting divisor and an annual divisor decrease. It shows each year's distribution and remaining balance, plus first-year, peak and total distributions.

You must supply the divisor that applies to your situation. The calculator does not look up an IRS life-expectancy table, determine a required beginning date, or handle inherited accounts, account aggregation, multiple-account rules or annuitized balances.

Inputs and units

Input Unit Accepted range What it means
Starting Age years 60 to 100 The age at which required distributions begin for you. Used to label the schedule and the charts.
Tax Rate On Distributions percentage 0–60% Optional. A flat tax percentage applied to distributions to estimate what you keep. Leave it blank and the tax outputs remain blank; distributions are then reported before tax.
Years To Project years 1 to 50 How many years of distributions to project.
First Divisor years 1 to 60 The life-expectancy divisor for your first distribution year, taken from the governing table for your age and circumstances. ILLUSTRATIVE: no table is reproduced here, and a wrong divisor gives a confidently wrong answer.
Account Balance $ 0 or more The balance the distribution is calculated on, which for a real distribution is the prior year-end value of the account.
Annual Divisor Decrease years 0 to 5 How much the divisor falls each year. Through the seventies and eighties it is close to nine tenths of a year annually; check it against the table for the ages you are projecting.
Expected Return percentage 0–25% The average annual return on the balance remaining after each distribution.

Governing relationships

In year k, the divisor is d(k) = max(1, d(1) - decrease × (k - 1)) and the required distribution is B(k) / d(k). After the distribution, the balance grows to B(k+1) = (B(k) - RMD(k)) (1 + r). The withdrawal percentage is 1 / d(k), so it rises as the divisor falls. That changing percentage explains why withdrawals can rise even while the account balance falls.

Calculation sequence

  1. Read the account balance, the starting age, the first divisor and its annual decrease, the years to project, the expected return and the tax rate.
  2. For each year, compute the divisor as the first divisor less the decrease for each year elapsed, floored at one.
  3. Divide the opening balance by that year's divisor to get the required distribution.
  4. Compute the required share as the reciprocal of the divisor.
  5. Subtract the distribution from the balance and grow the remainder at the expected return to get the next year's opening balance.
  6. Repeat across the projection period, accumulating the total distributed and tracking the largest single distribution.
  7. Apply the tax rate to the distributions to report the after-tax figure.
  8. Evaluate the status in the order given below.

Outputs and interpretation

The headline figures are Largest Distribution, Total Distributed and First Year Distribution. Everything else is supporting detail for those.

Output Role Unit What it means
Largest Distribution headline $/year The biggest single-year distribution over the period. It usually falls well after the first year, because the rising required share outruns the falling balance for a while.
Total Distributed headline $ Everything required to be withdrawn across the whole projection, before tax.
First Year Distribution headline $/year What you are required to withdraw in the first year.
Total After Tax detail $ What you would keep from the distributions after that tax. Blank until you supply a rate.
Total Tax On Distributions detail $ Tax on the distributions at the flat rate you supplied. Blank until you supply one.
First Year Percentage detail percentage The first distribution as a percentage of the opening balance, equal to one divided by the first-year divisor.
Ending Balance detail $ What is left in the account at the end of the period.
Age Of Largest detail years Your age in that year.
Final Divisor detail years The divisor in the last year projected, after the annual falls, floored at one.
Final Year Percentage detail percentage The distribution in the final projected year as a percentage of that year's opening balance. The second chart shows how this percentage rises over time.

Validation and status logic

The workbook evaluates status in this order, and the first condition that is true wins. The status text below is the exact wording the workbook returns; angle brackets mark a value substituted into the message at calculation time.

Condition Returned status
Account Balance <= 0 NOT VALID: there is no balance to distribute from
First Divisor <= 0 NOT VALID: the life-expectancy divisor must be above zero
Years To Project < 1 NOT VALID: project at least one year
Annual Divisor Decrease < 0 NOT VALID: the divisor falls each year, it does not rise
Expected Return < 0 NOT VALID: the expected return cannot be negative
Divisor in the final year <= 1.0000001 CHECK: the divisor has reached its floor of 1 within this period, so the whole balance is required in the final years
Ending Balance <= 0.01 CHECK: the account is exhausted before the end of the period
None of the preceding conditions applies OK

Assumptions and limitations

  • The first divisor and its annual decrease are inputs. They are illustrative values you supply, not a reproduction of any published life-expectancy table, and they must be checked against the table that applies to you.
  • The divisor is floored at one, at which point the whole remaining balance is required.
  • The return is constant and applies to the balance after the distribution is taken.
  • Tax is applied at a single flat rate to the distribution. Bracket effects, state tax, surcharges and the interaction with other income are outside the model.

Restrictions and non-computing states

The account balance must be greater than zero. The first divisor must be greater than zero, the annual decrease cannot be negative, and the projection must cover at least one year. The divisor is floored at one, at which point the whole remaining balance is required in that year. Starting age, expected return and tax rate are held within their published ranges.

Errors and warnings

A rejected entry means a value fell outside the published input rules, and no calculation was attempted. Workbook NOT VALID means the model ran and could not produce a meaningful answer, so the results are withheld. Workbook CHECK means the numbers stand but a condition is worth reading before you rely on them. A connection or calculation-service failure is an availability problem, not a finding of any kind, and never means zero.

References

Required minimum distribution rules, the applicable life-expectancy tables and the required beginning date are set by the Internal Revenue Service; see the required minimum distributions FAQs and Publication 590-B, Distributions from Individual Retirement Arrangements. The workbook reproduces no table from either source: the divisor is an editable input and the rule behind it is derived.

This model is arithmetic. It is not financial, tax, investment or retirement advice, and it is not a recommendation to save, invest, withdraw, claim or accept any amount. Decisions about retirement funding should be taken with a qualified professional who knows your circumstances.

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