Monthly retirement contribution calculator

What a steady monthly contribution could build by retirement

Move the four inputs and the projection redraws as you go. Contributions and assumed growth are drawn as separate bands, so you can see how much of the balance comes from deposits and how much from compounding. This is an educational illustration, not a forecast.

Compare contribution scenarios How the math works

Your inputs

Projected balance at retirement

$0

TodayHalfwayRetirement
  • Contributions
  • Assumed growth

Illustration only. Assumes the same contribution every month, a constant return, no fees and no taxes. Your results will differ.

Open notebook, pen, and calculator on a desk beside a printed savings chart
A quick pass on paper is still the fastest way to see how sensitive a plan is to the monthly amount.

01 / Assumptions

What the projection assumes

Read this before you compare scenarios. Every figure on this page comes from the notes beside it.

Full assumption detail

The calculator is an educational illustration. It shows how steady monthly contributions and a constant assumed return could compound over time. It is not a prediction, a quote, or a guarantee of future results.

  1. Constant contribution You add the same monthly amount every month until the retirement age you enter. No raises, no missed months, no catch-up deposits.
  2. Constant return The assumed annual return compounds smoothly at the same rate every year. Real markets do not move in a straight line.1
  3. No fees or taxes Fund expense ratios, advisory fees, and income taxes are excluded. Each of these lowers a real balance.2
  4. No inflation adjustment Results appear in today's purchasing power only if you set the return to a real, after-inflation figure.
  5. No personal data Nothing you type is stored or sent anywhere. There is no sign-up and no account.
How contributions and growth differ

Contributions are the dollars you put in. Growth is the return those dollars earn, and then the return earned by earlier growth. Early on, contributions dominate the balance. Later, growth usually overtakes them. The stacked chart above splits the two so you can see where the crossover falls at your numbers.

Limits worth knowing

A steady 7% return and a volatile 7% average can finish in very different places, because early losses hurt more than early gains help. Sequence risk, health costs, and future changes to Social Security sit outside this model. The limitations and disclaimer page lists the rest, and the financial disclaimer covers terms of use.

03 / Scenario matrix

One extra hundred a month moves the ending number

Set a starting monthly contribution, then compare it with two step-up levels. Every row uses the same 6% assumed annual return, so the only thing changing is what you add each month.

$400

Each cell shows a range built on 5% to 7% assumed annual returns, plus a 4% withdrawal illustration for yearly income. Amounts are nominal, before fees and taxes, and assume no missed contributions.

Try the interactive scenario tool
Projected balance and estimated first year income by monthly step-up
Monthly step-up1 Age 502 Age 602 Age 672
+$0 $106,920 – $126,760$4,674/yr $238,200 – $324,080$11,246/yr $377,960 – $571,400$18,987/yr
+$100 $133,650 – $158,450$5,842/yr $297,750 – $405,100$14,057/yr $472,450 – $714,250$23,734/yr
+$250 $173,745 – $205,985$7,595/yr $387,075 – $526,630$18,274/yr $614,185 – $928,525$30,854/yr

1Step-up is added the same month and never paused. 2Ages count from 35. 3Income uses 4% of the midpoint balance. A federal tax deferred account would change results.

05 Milestones

What $500 a month looks like at 10, 20 and 30 years

Same monthly contribution, same assumed 6% annual return, three different lengths of time. The longest stretch is where growth stops being a footnote and starts carrying the balance.

Illustration only, not a prediction. Constant $500 monthly contribution, 6% assumed annual return compounded monthly, no fees, no taxes, no inflation adjustment.

  1. 10years

    Projected balance$81,940

    Your contributions
    $60,000
    Assumed growth
    $21,940
  2. 20years

    Projected balance$231,020

    Your contributions
    $120,000
    Assumed growth
    $111,020
  3. 30years

    Projected balance$502,260

    Your contributions
    $180,000
    Assumed growth
    $322,260

Orange marks money you put in. Green marks the part the assumed return would add. Change the return or the monthly amount on the calculator above and every row here moves.

05 / FAQ

Fees, inflation, taxes and sequence risk, answered plainly

This calculator is an educational illustration, not a prediction. It holds your monthly contribution and assumed return steady and leaves fees and taxes out, so you can watch compounding work on its own. No sign-up, no personal data.

Want the long version? Read the assumptions in detail or check the glossary.

Questions and feedback

Ask about the assumptions behind your projection.

Tell us which contribution amount, return rate, or time horizon you are testing. We answer with plain arithmetic, not a promise of future returns.

Email [email protected]

Phone +1 (503) 965-5906

Office 4823 Financial District Ave, Suite 700, New York, NY 10005, United States

The methodology overview and the frequently asked questions cover constant returns, fees, and inflation first.