How much do I need to save?

How much do I need to save: what would it take each month?

Put in what you’re aiming for, how long you have and anything you’ve already saved, and see roughly what it would take each month. Every result is an illustration, not a forecast.

How much would you need to save each month?

Put in your goal, how long you have and anything you’ve already saved. See roughly what it would take each month, and how much of the goal would be growth.

Your numbers

£
What you’d like to have, in today’s pounds.
years
£
Leave at 0 if you’re starting from nothing.
%
An assumption, not a promise. Real returns go up and down, some years sharply. Try 0% to see what saving in cash alone would take.

Illustrative amount each month for 15 years, in today’s money

£0

You put in £0Growth £0
That’s more than £20,000 a year, the annual ISA allowance at the time of writing. Check gov.uk for the current limit.

How to read this

This works backwards from your goal, using the same maths as the ISA growth calculator: the monthly amount is added at the end of each month, and the whole pot grows at the same steady rate every year. Results are in today’s money, assuming what you put in rises with prices each year. The 5% starting rate is close to the long-run return on UK shares after inflation; an assumption, not a promise. Past performance is not a guide to the future. For a goal only a few years away, many people keep the money in cash, where growth after inflation may be close to zero: try 0% to see what that would take. Why the amount you put in matters most in the early years is in why savings rate matters more than returns.

How it works

Working back from a goal

Most calculators start with what you put in and show what it could become. This one starts with what you want and works back to the monthly amount, at the growth rate you choose.

01

Time does the heavy lifting

The longer you have, the more of the goal can come from growth rather than from you. Move the years from 10 to 20 and watch the monthly figure fall.

That’s the case for starting early, even with a small amount.

02

A head start counts twice

Money you’ve already saved grows for the whole period, so it lowers the monthly amount by more than its face value.

Put in what you have now and see how much it changes the answer.

03

The growth rate

It’s an assumption, not a promise. Over long periods UK shares have returned roughly 5% a year after inflation. Past performance is not a guide to the future, and real returns arrive unevenly, with some years sharply down.

The range under the result shows what 2 points either side would mean. I set out the long-run figures in what a realistic average return is.

Questions

Common questions

Quick answers about the figures. For your own circumstances, gov.uk and MoneyHelper have free guidance.

Is this the same as the ISA growth calculator?

It uses the same maths, run the other way. Put the monthly amount it gives into the ISA growth calculator with the same years, starting amount and rate, and you’ll get back to your goal, give or take rounding.

What growth rate does it use?

5% a year after fees and inflation to start with, close to the long-run return on UK shares after inflation. Past performance is not a guide to the future. You can change it. It’s an assumption, not a forecast, and real returns vary from year to year, sometimes below zero.

What if my goal is only a few years away?

Over short periods, investments can be down when you need the money, so many people keep short-term savings in cash. Set the growth rate to 0% to see what saving the whole amount would take without relying on growth.

Does it include my workplace pension?

No. It works out a monthly amount towards one goal. Your pension is separate, and money in it can’t be reached until later life. How pensions and ISAs work together is in the pension isn’t the whole plan.

Read next

Savings rate vs returnsWhy what you put in matters mostWhere your money goes firstThe order of operationsThe maths that changes everythingCompound returns explained

Rates used

All rates are at the time of writing and were checked at source on 3 November 2026. They’re updated each year on 6 April, and after any Budget that changes them.

What2026/27Source
ISA allowance£20,000 a year, shared across all your ISAsgov.uk: Individual Savings Accounts

Other calculators

ISA growthWhat your ISA could grow to with compound returns.Open the calculator →Salary calculatorYour take-home pay after tax, National Insurance, pension and student loan, then what part of it could do in an ISA.Open the calculator →Investment feesWhat a percentage or flat platform fee costs over the years.Open the calculator →ISA allowanceHow much of this year’s £20,000 you have left.Open the calculator →ISA tax savedThe dividend and Capital Gains Tax an ISA saves.Open the calculator →Lifetime ISAWhat the 25% bonus adds, and what the charge takes.Open the calculator →Market recoveryThe rise needed to recover from a fall.Open the calculator →

New to ISAs?

Read the sixteen articles in order.

Getting Started takes you from the basics to opening your ISA, then the principles that keep you invested and how wealth builds over time.

Go to Getting Started

All results are illustrations, not forecasts, and not financial advice. They assume steady rates that real markets never deliver. The value of investments can go down as well as up, and you can get back less than you put in. Allowances, tax rates and ISA rules can change, so always check gov.uk for the current figures.

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