Free Retirement Calculator: How Much You Need to Save (2026)

Retirement Planning

Worked Example

A 35-year-old planning to retire at 67 with $50,000 already saved, a $60,000/year spending goal, and a $24,000/year Social Security estimate needs roughly $900,000 saved by retirement, and about $303/month in new contributions to get there at a 7% average return. The $50,000 already invested does a lot of the work on its own over 32 years of growth, which is why the monthly number is lower than the total target might suggest.

How a Retirement Savings Calculator Works

Five inputs, no account or email required.

Current age and retirement age. These set how many years your contributions have to grow. The default retirement age is 67, the standard full retirement age for Social Security, but you can test 60, 65, or 70 to see how the timeline changes your monthly number.

Current retirement savings. Whatever you already have in 401(k)s, IRAs, and other retirement accounts combined. This amount keeps growing on its own at the assumed return rate, which lowers how much new monthly savings you need.

Annual spending goal in retirement. Not your current salary, what you expect to actually spend per year once you've stopped working.

Expected annual Social Security income. If you don't know your number yet, the 2026 average for retired workers is roughly $24,000/year, according to the Social Security Administration. For a personalized estimate based on your actual earnings record, use SSA's official benefit calculators before relying on the average.

How the Math Works

The calculator runs two calculations behind the scenes.

Required portfolio: (Annual spending − Social Security) × 25. This comes from the 4% rule, a guideline originally developed by financial planner William Bengen and later expanded in the Trinity Study, suggesting a diversified portfolio can sustainably support a 4% annual withdrawal rate over a roughly 30-year retirement. Multiplying by 25 is the same math stated as a multiple instead of a percentage.

Monthly savings needed: a standard compound growth calculation. It projects how much your current savings will grow on their own by retirement age at a 7% average annual return, a reasonable long-run planning rate for a stock-heavy portfolio, then calculates the monthly contribution required to make up the remaining difference.

How Retirement Age Changes Your Monthly Number

Using the same retirement savings calculator inputs as the worked example above (age 35, $50,000 saved, same $900,000 target), retiring later instead of earlier has a large effect on the monthly figure, mainly because it changes both how long contributions grow and how long they need to last.

Social Security isn't actually available before age 62, so the 60 row assumes you'd cover the gap from savings alone for the first two years. Treat these as directional, not exact.

Assumptions and Limitations

Every number this retirement savings calculator produces is a planning estimate, not a guarantee.

It assumes a 7% average annual return. That's a reasonable long-run historical average for a diversified stock-heavy portfolio, but actual returns vary year to year, and a more conservative or more aggressive assumption will move the monthly number meaningfully in either direction.

It doesn't account for taxes. Whether your eventual withdrawals are taxed depends on which accounts the money sits in, traditional or Roth. The calculator estimates the pre-tax portfolio size needed, not your after-tax spending power.

It uses your input for Social Security, not a guarantee from SSA. Estimate accuracy depends on how close your input is to your actual future benefit. For the full picture of how benchmarks vary by age, see retirement savings by age.

It assumes a level spending pattern. Real retirement spending isn't flat, often higher in the early years, lower in the middle, higher again later for healthcare. This calculator gives a single target number, not a year-by-year spending plan.

What to Do With Your Number

Once this retirement savings calculator gives you a target portfolio and a monthly savings figure, the next question is usually whether that number is realistic right now. For the full reasoning behind the 4% rule, the 10x-salary alternative, and how Social Security changes the picture, see how much to save for retirement.

FAQ