Retirement Projection Checklist: 8 Inputs to Get Right

A retirement projection is most sensitive to a handful of inputs: how many years you have left to save, how much you add, the return you assume, inflation, and the income you plan to draw. Small changes to any of them can move the age your savings run out by five years or more. Check them one by one before trusting the headline number.

The checklist below uses the Retirement Calculator's default example as a baseline: age 35, retiring at 67, planning until 90, 50,000 saved, 500 a month, 6% before retirement, 4% during, 2.5% inflation, and 40,000 a year of income wanted in today's money. That baseline projects 918,260.68 at retirement, worth 416,679.65 in today's money, and the wanted income runs out around age 78. All figures are estimates under steady-return assumptions, not financial advice, and this guide doesn't recommend any particular investment.

1. Are your three ages in the right order?

Current age, Retirement age and Plan until age must increase, and the last one can be at most 120. Retiring two years earlier, at 65, cuts the projection to 803,386.28 and moves the run-out age from about 78 to about 75: two fewer years of saving and two more years of spending.

2. Is your current balance the retirement money only?

Enter what is actually earmarked for retirement in Current retirement savings. Including an emergency fund or a home deposit makes the projection look better than it is. The starting balance is kept separate from Your contributions until retirement, which counts only the monthly payments: 500 a month for 32 years shows as 192,000.00.

3. Is the monthly contribution realistic?

Use the amount you reliably save, including any employer contribution you receive. Raising Monthly contribution from 500 to 800 lifts the projection to 1,265,564.95 and pushes the run-out age to about 83.

4. Is the return before retirement cautious enough?

Return before retirement compounds for decades, so it has a large effect. Lowering it from 6% to 5% drops the projection from 918,260.68 to 719,221.21, and the money now runs out around 75. A slightly lower assumption gives a plan that is less likely to disappoint.

5. Have you set a separate return for retirement?

Return in retirement applies while you withdraw. It is often set lower than the pre-retirement figure. Dropping it from 4% to 3% moves the run-out age from about 78 to about 77, a smaller effect than the saving-phase return, because the balance is shrinking.

6. Is inflation switched on?

This is the input most likely to make a plan look rosier than it is. Set Inflation to 0 and the same savings appear to last beyond age 90. At 2.5%, prices over 32 years rise by the same factor that shrinks 918,260.68 into 416,679.65, so the 40,000 you want today becomes a much larger withdrawal by the time you retire, and it keeps growing every year after that. Leave inflation on.

7. Is the wanted income only what savings must cover?

Yearly income wanted in retirement is in today's money and should exclude pensions or state benefits. If you expect a pension to cover part of your costs, subtract it first. Lowering the figure from 40,000 to 30,000 stretches the money to about 83; at 25,000 it lasts until about 86. Set it to 0 and the check simply reads "Not set."

8. Do you know what the withdrawal rate controls?

Withdrawal rate drives only the "Income at … withdrawal" line, which shows a sustainable yearly income as a share of the projected balance. At 4% that is 36,730.43 a year, or 16,667.19 in today's money; at 3.5% it is 32,139.12. The run-out age comes from the separate drawdown check, which withdraws your wanted income, rising with inflation, while the remainder earns the retirement return. Comparing the two lines tells you how far your wanted income sits above a cautious withdrawal.

How to run the checklist in the calculator

The Retirement Calculator recalculates as you change any field:

1. Fill in the three ages, your current savings and your monthly contribution.
2. Set the two returns, inflation, your wanted yearly income and a withdrawal rate.
3. Read Savings at retirement, In today's money, the income line and whether the wanted income lasts or runs out.
4. Expand Balance by age for the year-by-year balance, labelled Saving or Withdrawing. Balances there are in future money, not today's.

Change one input at a time to see which assumption your plan depends on most. Your figures stay in your browser.

Starting age matters too. With everything else at the baseline, beginning at 25 projects 1,752,620.15; beginning at 45 projects 459,669.40. For shorter goals along the way, the Savings Goal Calculator works out a monthly target, and the Compound Interest Calculator shows growth year by year without the retirement phase.

What the projection does not include

Steady returns are a simplification; real markets rise and fall. Taxes, fund fees, pensions and state benefits are also outside the model. Adjust the inputs to reflect them, or treat the result as a rough upper bound.

FAQ

What does "Runs out around age 78" mean exactly?

The balance is still positive at 78 but cannot cover the following year's withdrawal. In the Balance by age table, age 78 shows 77,453.51 and age 79 shows 0.00.

Why doesn't changing the withdrawal rate change the run-out age?

The run-out age is based on the income you say you want, not on the withdrawal rate. The withdrawal rate only sizes the suggested sustainable income.

Should I plan until 90, 95 or 100?

Longer is more cautious. In the baseline it makes no difference, because the money runs out at 78 either way, but when savings stretch further, a later plan-until age shows whether they hold.

Test your own assumptions, one input at a time, in the Retirement Calculator.