Comprehensive Guide
Learn more in our Personal Finance Guide.
How it works
The calculator simulates 35 years of monthly compounding: each month your balance earns one-twelfth of the annual return, then your contribution lands. With an annual step-up, each year's contribution is the previous year's scaled by the step-up percentage — modelling raises that land in your retirement account before lifestyle inflation eats them. The engine also totals what you personally put in, so the growth number shows what compounding did for you versus what you did for yourself. A 7% assumption roughly matches the long-run US stock-market average after inflation; a safer 5-6% is sensible if you tilt toward bonds. The gap between the contributions slice and the corpus slice is the entire argument for starting early — the same total invested decades earlier grows several times larger, because growth compounds on growth. Every field in this calculator exists for a reason. Enter Current age, Retirement age, Current retirement savings, Monthly contribution, Expected annual return, and the engine recomputes the results instantly — no signup, no email, and nothing is sent to a server, because the math runs entirely in your browser. Change one input at a time to see which lever moves the result most; that sensitivity, not any single number, is usually the real insight. The worked example below the form uses realistic defaults so you can sanity-check the output before trusting it with your own figures, and the formula is published on the page so you can verify every step of the arithmetic yourself.Formula
Balance each month = Balance x (1 + rate/12) + contribution
Tips
- A 1% annual step-up barely hurts today's budget yet adds years of compounding later.
- Check your employer match first — it is free money that beats any return assumption.
- Re-run the tool after every raise and retire the difference, not tomorrow's lifestyle.
- In your fifties, model a lower return (5%) to plan conservatively.
Frequently asked questions
How much should I have saved for retirement by 30?
A common benchmark is one times your salary by 30, three times by 40. What matters more is the trajectory: if your projected corpus covers roughly 25 times your annual spending at retirement age, you are on the classic 4% withdrawal path.
What return should I assume?
A 6-8% long-run average is reasonable for a diversified stock-heavy portfolio before inflation; after inflation, 4-6%. Use the lower end if you are near retirement, because a sequence of bad early returns matters more when withdrawals start.
Is the 4% withdrawal rule still valid?
It remains the standard first estimate: a portfolio can historically survive roughly 30 years of 4% inflation-adjusted withdrawals. Build your corpus target as 25 x your expected annual spending, then adjust for your own risk tolerance.
What is a good annual step-up?
Matching your expected pay rises, typically 2-4%. Even a 1% step-up compounds into a materially larger corpus over 30 years, because the increase happens every year, not once.