Savings Goal Calculator

Have a goal in mind — house deposit, wedding, sabbatical, emergency fund? Solve for the missing piece: how much to save each month, how long it'll take, or how much you'll have at the end.

The three questions a savings plan has to answer

Every savings goal can be expressed as a relationship between four numbers: how much you have now, how much you contribute each month, what return you earn, and how long you save. Fix any three and the fourth is determined. This calculator lets you choose which one to solve for:

• Required monthly contribution — when you have a deadline (a house deposit by 2029, a wedding next summer) and need to know what to put away each month.
• Years to reach goal — when you can only afford a fixed amount per month and need to know how long until you hit the target.
• Final amount — when you want to project where you'll be if you stick to a plan, with no fixed end goal.

How the math works

The future value of regular savings combines two pieces: the future value of money you already have, and the future value of all the contributions you'll add along the way. With monthly rate r = annual return ÷ 12, current balance P, monthly contribution C, and n months:

FV = P · (1 + r)n + C · ((1 + r)n − 1) / r

To solve for the contribution C, rearrange:

C = (FV − P · (1 + r)n) · r / ((1 + r)n − 1)

To solve for time n:

n = log((FV · r + C) / (P · r + C)) / log(1 + r)

Worked example

Say your target is £50,000 for a house deposit, you've already saved £5,000, you have 8 years, and you expect 5% annual return in a balanced index fund. Plug in: with r = 0.00417 and n = 96 months, your £5,000 grows to about £7,460 on its own, leaving £42,540 to come from contributions. C ≈ £42,540 × 0.00417 ÷ (1.00417⁹⁶ − 1) ≈ £363/month. Total contributed: about £34,850; the remaining £10,150 comes from returns.

Where to actually put the money

Short goals (under 2 years) live in cash. Bank savings accounts, high-yield money market funds, or fixed-term deposits. Returns will be roughly the central bank rate ± 1%. You can't afford a market downturn between you and the goal.

Medium goals (2-7 years) sit in a mix. Mostly cash and short-dated bonds, with a smaller equity allocation. You can take some risk for slightly better returns, but a major loss right before the goal is recoverable only if you have flexibility on the deadline.

Long goals (7+ years) belong in diversified equities. Historical real returns of 5-7% per year reward the patience. Stick the money in a low-cost global index fund and don't check it more than annually.

Inflation matters

A £50,000 house deposit goal set in 2026 is not the same as £50,000 in 2034. If inflation runs at 3% per year, that same deposit needs to be about £63,000 in eight years to buy the same house. To plan in real terms, subtract your expected inflation rate from the return rate (so 5% nominal − 3% inflation = 2% real). The required monthly contribution will be higher, but the goal will preserve its purchasing power.

What this calculator does NOT model

• Variable contributions (e.g., increasing your savings as your income grows)
• Taxes on returns (ISA, Roth IRA, regular brokerage all differ)
• Fund fees, platform fees, or transaction costs
• Currency risk if you're saving in one currency and spending in another
• Withdrawals before reaching the goal

Disclaimer

Educational only. Returns are not guaranteed — short-term volatility can cause real outcomes to differ significantly from this projection. For a money goal that genuinely matters (down payment, wedding, emergency fund), use a conservative return assumption and review your progress at least annually.