Savings rate calculator

Why savings rate is the master number

Of all the levers in personal finance, your savings rate matters most - because it works on both ends of the equation at once. Saving more builds your portfolio faster and lowers the spending you need to replace, which shrinks your FIRE target. That double effect is why two people with very different incomes can retire in the same number of years if they save the same percentage.

The math

This calculator turns a savings rate into a timeline:

1. Savings rate = annual savings ÷ take-home pay.
2. Annual spending = take-home pay − savings.
3. FIRE number = spending ÷ safe withdrawal rate.
4. Years to FI = how long it takes, starting from zero, to invest your annual savings up to that FIRE number at your real return.

Worked example

Take-home pay of $100,000, saving $50,000 a year, at a 5% real return and a 4% withdrawal rate:

• Savings rate: 50%
• Annual spending: $50,000
• FIRE number: $50,000 ÷ 4% = $1,250,000
• Years to financial independence: about 17 years - from a standing start

Notice the income barely matters: someone earning $200,000 and saving 50% ($100,000) reaches their own (larger) target in the same ~17 years, because their spending and target scale together.

The savings-rate-to-years relationship

A rough sense of how the rate bends the timeline (5% real return, from zero):

• 10% saved: ~50+ years
• 25% saved: ~32 years
• 50% saved: ~17 years
• 65% saved: ~10.5 years
• 75% saved: ~7 years

Each step up in savings rate cuts the timeline far more than a raise would.

How to use the result

Slide your savings up and watch the years fall. The fastest gains come from cutting recurring spending (it lifts the rate and lowers the target at once) rather than from earning more and spending it. High earners benefit most by keeping lifestyle creep in check as income rises.

Common mistakes

• Measuring savings rate against gross pay, which flatters the number.
• Assuming a raise shortens the timeline - it only helps if you save it.
• Ignoring that one-off windfalls (bonuses, RSU vests) can meaningfully raise the effective rate if invested.

To project the exact date, use the FIRE calculator; to choose the withdrawal rate behind your target, see the safe withdrawal rate calculator.