Saving for a child calculator
This calculator projects a savings pot for a child from a monthly amount, a starting balance and an assumed annual growth rate, compounding month by month to the target age. On the default plan of £100 a month at 5% to age 18, the pot reaches £34,526, of which £12,926 is growth rather than money paid in.
Projections are not guarantees. Investment returns vary year to year and the pot is in future pounds, not today’s money.
How does the savings projection work?
Each month the tool adds your contribution to the pot and grows the running balance by one month’s share of the annual rate. Repeating that to the target age captures compounding, where growth in early years itself earns growth later on. The longer the horizon, the more the final pot leans on growth rather than on what you paid in, which is the main argument for starting young.
The cash and stocks figures on the right use 3% and 7% so you can see how much the rate matters over a long period. Neither is guaranteed. Cash is steadier but usually lower, while a stocks and shares approach has historically returned more with real falls along the way. Because the projection uses headline rates, the pot is in future pounds; treat a lower rate as the cautious, closer-to-today’s-money view.
How much will I have if I save for my child?
Start from nothing and save £100 a month from birth to 18 at 5% a year. You pay in £21,600 over the 18 years, and the pot grows to £34,526, so growth adds about £12,926. At 3% the same saving reaches £28,482, and at 7% it reaches £42,092. The gap between those two shows why the growth assumption deserves as much thought as the monthly amount.
Common questions
How much will I have if I save for my child?
It depends on the monthly amount, how long you save and the growth rate. As a rough guide, £100 a month from birth to 18 at 5% a year grows to around £35,000, of which roughly £13,000 is growth on top of what you paid in. Change the inputs to match your own plan.
How does the savings projection work?
Each month the calculator adds the contribution to the running pot and grows the balance by one month’s share of the chosen annual rate, so it captures compounding over the whole period. The figure produced for the target age is a projection built on that assumed rate, not a guarantee, since actual savings or investment returns move up and down from year to year and can differ substantially from any single assumption used here.
What growth rate should I use?
A cash account might return around 3% before tax, while a diversified stocks and shares investment has historically returned more but with rises and falls along the way. The default here is a middle figure of 5%. Lower it if you want a cautious estimate; no rate is guaranteed.
Is this only for a Junior ISA?
No. This is a general projection, so it works for any account: a Junior ISA, a savings account, or investments held for a child. A Junior ISA has a £9,000 a year limit and locks the money until 18, which a plain savings account does not, so pick the wrapper that fits your goal.
Does the projection account for inflation?
No. The figure is in today’s money terms only if you treat the growth rate as a real, after-inflation return. If you use a headline rate like 5%, the pot is in future pounds, which buy less than the same number today. For a cautious view, use a lower rate.
When can the child access the money?
That depends on the account. A Junior ISA becomes the child’s at 18 and cannot be accessed before then. Money in an ordinary savings or investment account in your name stays under your control, so you decide when and how it is handed over.
Sources & Rate Verification
Rates verified against official statutory guidance on 6 September 2026.