Retirement Calculator
Enter your age, retirement age, current savings, what you invest each month and what you spend. The calculator projects your savings at retirement, the amount needed to cover your spending, and the surplus or shortfall.
Retirement Details
Pre-retire return
%Post-retire return
%Inflation
%Projected Corpus at Retirement
$1.19M
Required: $1.87M
From existing savings
$287,654
From monthly investing
$905,780
Sustainable monthly income
$6,299
How It Works
The calculator grows your current savings and monthly investing at the return you expect before retirement, compounded monthly. It then raises today's monthly spending by inflation until the year you retire and works out how big a pot has to be to pay that amount every month until your life-expectancy age, earning a lower return in retirement. With the starting numbers (age 30, retiring at 65, $25,000 saved, $500 invested a month, 7% before and 4% after retirement, 3% inflation) the projected pot is about $1.19 million. $3,500 a month of today's spending becomes about $9,849 a month by 65, and covering that to age 90 takes about $1.87 million, a gap of roughly $672,000, or about $371 more invested each month. Government pensions such as Social Security, the UK State Pension or the Canada Pension Plan are not counted, so for many people the real gap is smaller. Every assumption is an input you can change.
Formula
Savings at retirement = S × (1 + r)^n + M × [((1 + r)^n − 1) / r] × (1 + r), with monthly r and n months to retirement. Needed = inflated monthly spending × [1 − (1 + q)^−m] / q, where q is the monthly return after retirement and m is the number of months in retirement.
Frequently Asked Questions
How much do I need to retire?
It depends on what you spend, how long retirement lasts and what your savings earn. A common rule of thumb is 25 times your annual spending, the so-called 4% rule: at $3,500 a month ($42,000 a year) that is $1,050,000 in today's money. The rule ignores how long you will be retired and when. This calculator projects your actual spending at retirement and the years you need to cover, so use the two as a cross-check.
What return should I assume?
Be conservative. Stocks have historically returned more than bonds over long periods, but nothing is guaranteed. The calculator starts at 7% before retirement and 4% after as examples. Try lower values, such as 5% and 3%, to see how sensitive the result is.
What does sustainable monthly income mean?
It is the amount your projected savings could pay out each month until the life-expectancy age, at the return you chose for retirement. In the example that is about $6,299 a month, measured in the money of the year you retire, not today's money.
Does this include Social Security or a pension?
No. Government and employer pensions are left out so you can see what your own savings have to cover. If you expect a pension, subtract it from your monthly spending before you enter it.
How does inflation change my retirement number?
A lot over long periods. $3,500 a month today becomes about $9,849 a month in 35 years at 3% inflation, and about $7,000 at 2%. That is why the amount needed at retirement is much larger than a simple multiple of today's spending.
How much should I save each month?
If there is a shortfall, the calculator shows how much more to invest each month. In the example it is about $371. Starting earlier needs less per month, because every deposit has more years to compound.