The 10% savings rule is one of the most widely recommended starting points in personal finance — save 10% of whatever you earn, consistently, and let time do the rest. It's simple enough to remember, flexible enough to work on almost any income, and effective enough that it's been the go-to advice for decades.
This calculator shows what 10% of your income actually amounts to in pounds — monthly and annually — and what that figure could grow to over time if it's put into a savings account or ISA earning interest. You can also adjust the percentage if 10% isn't realistic right now, or if you want to see what saving more would look like.
The rule isn't magic, and it isn't the only approach — but as a starting point, it gives you a concrete number to aim for rather than a vague intention to "save more." That specificity is what makes it useful.
Where the 10% Rule Comes From
The 10% rule isn't from a single source — it's a principle that's been repeated in personal finance writing for well over a century, most famously in George Clason's 1926 book The Richest Man in Babylon, which advised paying yourself first by setting aside a tenth of your earnings before spending anything else.
The reason it's endured is that it scales. Ten percent of £1,200 a month is £120. Ten percent of £4,000 a month is £400. The amount looks very different, but the principle is identical — and both amounts, saved consistently over time, grow into something meaningful.
It's also psychologically reasonable. Most people can adjust to living on 90% of their income without it feeling catastrophic. The same can't always be said for 20% or 25%, which is why more aggressive saving rules often don't stick.
What If 10% Isn't Possible Right Now?
The 10% figure is a target, not a requirement. If you're currently saving nothing — which is the situation many people are in, through no fault of their own — then 1% is better than 0%. Two percent is better than 1%. The habit of saving regularly matters as much as the amount, especially at the beginning.
Start with whatever you can manage consistently. Even £20 a month, kept up reliably for years, builds into something. The calculator lets you try different percentages — drop it to 3% or 5% and see what that looks like over ten years. It's often more than people expect.
Once saving becomes a habit rather than an effort, gradually increasing the percentage becomes easier. Many people find that when their income goes up — a pay rise, a better job, reduced childcare costs — they increase their savings rate instead of increasing their spending proportionally. This is sometimes called "lifestyle deflation" and it's one of the most effective ways to build wealth over time without feeling like you're depriving yourself.
If 10% feels out of reach, start with 3%. At £2,000 take-home, that's £60 a month — £720 a year. After five years with interest, that's over £3,900. Small numbers, real money.
Where to Put the 10%
The 10% rule tells you how much to save. It doesn't tell you where to put it — and where you put it affects how much it grows.
For most people starting out, a straightforward easy-access savings account is the right first step. The money is accessible if you need it, earns interest, and keeps savings separate from day-to-day spending. Once you have a few months of expenses saved as an emergency buffer, other options become worth considering.
A Cash ISA keeps your savings interest tax-free — worth looking at if your savings are growing to the point where the interest becomes meaningful. A regular saver account from certain banks offers significantly higher interest rates, though with a monthly deposit cap and restrictions on withdrawals — our regular saver accounts guide explains how these work.
For longer-term saving — ten years or more — Stocks and Shares ISAs or pension contributions may be worth exploring, though these involve a different level of complexity and risk. Our pension basics guide covers workplace pensions in plain English.
The Power of Starting Early
The growth projection in the calculator demonstrates something that's mathematically true but often underestimated: the earlier you start, the more time compound interest has to work.
Saving £150 a month from age 25 produces a very different outcome at age 65 than saving £300 a month from age 45 — even though the second person is saving twice as much per month. The first person wins, significantly, because of the extra twenty years of compounding.
This isn't meant to make anyone who's starting later feel bad — starting at any age is better than not starting. But it is a genuine reason not to put it off. The best time to start saving was yesterday. The second best time is now.
Frequently Asked Questions
Take-home pay is the more practical figure to work with — it's what actually arrives in your account. Some versions of the rule refer to gross income, but since you can't spend your gross income, basing your savings target on take-home pay gives you a more realistic number.
The traditional framing is "pay yourself first" — meaning the 10% goes aside before you spend on anything else, including bills. In practice, most people find it easier to work out their safe to spend figure first, then direct 10% of that into savings. Either approach works as long as the saving actually happens.
This depends on the interest rate on the debt. High-interest debt — credit cards, payday loans — almost always costs more than savings earn, so paying that down first makes mathematical sense. Lower-interest debt like student loans or mortgages is less clear-cut. Doing both — making minimum debt payments while building a small savings buffer — is a reasonable middle ground that many financial advisers suggest.
The projection uses a nominal interest rate, not an inflation-adjusted one. The real-terms value of your savings will be lower than the nominal figure shown if inflation is running above your interest rate. For a rough real-terms figure, subtract the current inflation rate from the interest rate you've entered.
Start with whatever you can manage consistently. Even 1% or 2% builds a habit. Use the slider to see what smaller percentages look like over time — it's often more than people expect. Increase gradually as your circumstances allow.
This calculator provides projections for illustrative purposes only. Interest rates vary and are not guaranteed. This is not financial advice. For free guidance visit MoneyHelper or Citizens Advice.