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Pension Calculator

Compare a pension's lump sum with monthly payments, single life with joint and survivor, and starting early with starting later.

Change the values and press Calculate to work out your own figures.

Lump sum or monthly

Enter the lump sum, the monthly pension, the return and COLA.

When you stop working.
Paid at retirement.
Before tax.
First year's payment.
Changes how amounts are shown, not the math; your choice is remembered on this device.
0 if blank; Social Security's 2026 COLA was 2.8%.
Result
Lump sum runs out
Age 80 years 1 month

Paying yourself the pension's income, the lump sum lasts until about 80 years 1 month. If you expect to live longer, the pension pays more.

Show the working
  1. balance = balance × (1 + monthly return) − pension × (1 + COLA)^years

Single life or joint and survivor

Enter both pensions, your ages and life expectancies.

When you stop working.
Age to plan to.
For example 62.
For example 82.
Stops at your death.
Continues to your spouse.
Before tax.
Changes how amounts are shown, not the math; your choice is remembered on this device.
0 if blank; Social Security's 2026 COLA was 2.8%.
Result
Better value
Single life
Single life, value at retirement
$648,730.21 (12 years of payments)
Joint and survivor, value at retirement
$613,799.48 (20 years of payments)

Single life is worth $34,930.73 more at retirement.

Show the working
  1. value = Σ pension × (1 + COLA)^years ÷ (1 + monthly return)^months

Start early or later

Enter two start ages and their pensions.

For example 60.
For example 2,500.
For example 65.
For example 3,800.
Before tax.
Changes how amounts are shown, not the math; your choice is remembered on this device.
0 if blank; Social Security's 2026 COLA was 2.8%.
Result
Break-even
Age 86 years 7 months
Starting at 60
$2,500.00 a month
Starting at 65
$3,800.00 a month

Starting at 65 pays more in total if you live past 86 years 7 months.

Show the working
  1. running totals of both options, each payment valued at the earlier start age

How to use it

Enter the lump sum, the monthly pension, the return and COLA. Enter both pensions, your ages and life expectancies. Enter two start ages and their pensions.

Enter amounts without commas or with them; rates are percentages (5 for 5%). Negative amounts are allowed where a sign means money paid out.

Key facts

lump sum lasts while balance × (1 + monthly return) − pension stays above 0
value = Σ pension × (1 + COLA)^years ÷ (1 + monthly return)^months

Questions

Should I take the lump sum or the pension?

Compare how long the lump sum would last paying the same income with how long you expect to live.

Reviewed by RK Calculator Team. Updated 2026-09-26.

Formulas

lump sum lasts while balance × (1 + monthly return) − pension stays above 0
value = Σ pension × (1 + COLA)^years ÷ (1 + monthly return)^months

Sources

Limitations

  • Results are estimates for planning, not offers or financial advice; lenders and banks may round, count days or time payments differently.
  • Rates are nominal annual rates compounded as you choose; payments at a different frequency use the equivalent periodic rate.

Formula version 0.1.0Reviewed