Investment Calculator
Enter a starting amount and see, in one table, how it would grow over 20 years at annual returns from 1% to 10% — every rate and every year at once, updating instantly as you type.
Calculator
Calculator
Growth over 20 years, by annual rate
| Year | 1% | 2% | 3% | 4% | 5% | 6% | 7% | 8% | 9% | 10% |
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | £10,100.00 | £10,200.00 | £10,300.00 | £10,400.00 | £10,500.00 | £10,600.00 | £10,700.00 | £10,800.00 | £10,900.00 | £11,000.00 |
| 2 | £10,201.00 | £10,404.00 | £10,609.00 | £10,816.00 | £11,025.00 | £11,236.00 | £11,449.00 | £11,664.00 | £11,881.00 | £12,100.00 |
| 3 | £10,303.01 | £10,612.08 | £10,927.27 | £11,248.64 | £11,576.25 | £11,910.16 | £12,250.43 | £12,597.12 | £12,950.29 | £13,310.00 |
| 4 | £10,406.04 | £10,824.32 | £11,255.09 | £11,698.59 | £12,155.06 | £12,624.77 | £13,107.96 | £13,604.89 | £14,115.82 | £14,641.00 |
| 5 | £10,510.10 | £11,040.81 | £11,592.74 | £12,166.53 | £12,762.82 | £13,382.26 | £14,025.52 | £14,693.28 | £15,386.24 | £16,105.10 |
| 6 | £10,615.20 | £11,261.62 | £11,940.52 | £12,653.19 | £13,400.96 | £14,185.19 | £15,007.30 | £15,868.74 | £16,771.00 | £17,715.61 |
| 7 | £10,721.35 | £11,486.86 | £12,298.74 | £13,159.32 | £14,071.00 | £15,036.30 | £16,057.81 | £17,138.24 | £18,280.39 | £19,487.17 |
| 8 | £10,828.57 | £11,716.59 | £12,667.70 | £13,685.69 | £14,774.55 | £15,938.48 | £17,181.86 | £18,509.30 | £19,925.63 | £21,435.89 |
| 9 | £10,936.85 | £11,950.93 | £13,047.73 | £14,233.12 | £15,513.28 | £16,894.79 | £18,384.59 | £19,990.05 | £21,718.93 | £23,579.48 |
| 10 | £11,046.22 | £12,189.94 | £13,439.16 | £14,802.44 | £16,288.95 | £17,908.48 | £19,671.51 | £21,589.25 | £23,673.64 | £25,937.42 |
| 11 | £11,156.68 | £12,433.74 | £13,842.34 | £15,394.54 | £17,103.39 | £18,982.99 | £21,048.52 | £23,316.39 | £25,804.26 | £28,531.17 |
| 12 | £11,268.25 | £12,682.42 | £14,257.61 | £16,010.32 | £17,958.56 | £20,121.96 | £22,521.92 | £25,181.70 | £28,126.65 | £31,384.28 |
| 13 | £11,380.93 | £12,936.07 | £14,685.34 | £16,650.74 | £18,856.49 | £21,329.28 | £24,098.45 | £27,196.24 | £30,658.05 | £34,522.71 |
| 14 | £11,494.74 | £13,194.79 | £15,125.90 | £17,316.76 | £19,799.32 | £22,609.04 | £25,785.34 | £29,371.94 | £33,417.27 | £37,974.98 |
| 15 | £11,609.69 | £13,458.68 | £15,579.67 | £18,009.44 | £20,789.28 | £23,965.58 | £27,590.32 | £31,721.69 | £36,424.82 | £41,772.48 |
| 16 | £11,725.79 | £13,727.86 | £16,047.06 | £18,729.81 | £21,828.75 | £25,403.52 | £29,521.64 | £34,259.43 | £39,703.06 | £45,949.73 |
| 17 | £11,843.04 | £14,002.41 | £16,528.48 | £19,479.00 | £22,920.18 | £26,927.73 | £31,588.15 | £37,000.18 | £43,276.33 | £50,544.70 |
| 18 | £11,961.47 | £14,282.46 | £17,024.33 | £20,258.17 | £24,066.19 | £28,543.39 | £33,799.32 | £39,960.19 | £47,171.20 | £55,599.17 |
| 19 | £12,081.09 | £14,568.11 | £17,535.06 | £21,068.49 | £25,269.50 | £30,256.00 | £36,165.28 | £43,157.01 | £51,416.61 | £61,159.09 |
| 20 | £12,201.90 | £14,859.47 | £18,061.11 | £21,911.23 | £26,532.98 | £32,071.35 | £38,696.84 | £46,609.57 | £56,044.11 | £67,275.00 |
How it's worked out
Each cell uses the standard compound-growth formula, applied once a year (no monthly compounding, unlike the loan calculator):
Value after n years = Starting amount × (1 + annual rate ÷ 100)ⁿ
The table repeats this for every whole rate from 1% to 10% and every year from 1 to 20, so you can compare how much the rate itself changes the outcome over a long horizon.
This is a plain mathematical projection, not a promise: it doesn't account for inflation, tax, fees, or the fact that real investments can lose value as well as gain it. Treat it as a way to compare rates and time horizons, not a guaranteed return.
Worked example
Suppose you start with £10,000. At a steady 5% a year, it grows to about £12,762.82 after 5 years, £16,288.95 after 10 years, and £26,532.98 after 20 years.
The rate matters more than it looks: the same £10,000 over the same 20 years would reach only about £12,201.90 at 1%, but about £67,275.00 at 10% — more than five times as much, purely from the difference in rate compounding year after year.
Frequently asked questions
How is the growth in each cell worked out?
We multiply your starting amount by (1 + rate ÷ 100), raised to the power of the number of years, once for each rate (1% to 10%) and each year (1 to 20). This is ordinary annual compounding: each year's growth is added to the balance before the next year's growth is worked out.
Why does a small difference in rate make such a big difference after 20 years?
Compounding means each year's growth is worked out on an already-larger balance than the year before, so small rate differences multiply themselves over time. Over a few years the gap is small; over 20 years it becomes large, which is why the rate you actually get matters more the longer you hold an investment.
Does this account for inflation, tax, or fees?
No — this shows pure mathematical compound growth at a rate you choose to compare, nothing else. Real investments also involve risk (including losing value), and real returns are reduced by inflation, tax, and fees, so treat these figures as a comparison tool, not a forecast of what any real investment will do.
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For information only. This is not financial or tax advice.