Savings Projection by Rate Calculator

400/month for 20 years: at 3% grows to 131,000; at 5% 165,000; at 7% 208,000. 4 percentage point gap = 77,000 over 20 years. Return assumptions are more impactful than most people realise over long horizons. Choose conservatively when planning; revise up if reality exceeds.

Run it with sensible defaults

Using monthly savings of 400, horizon of 20, the calculation works out to 208,370.66. The defaults are meant as a starting point, not a recommendation.

The levers in this calculation

The inputs — Monthly Savings and Horizon — do not pull with equal force. Not every input has equal weight. Adjusting one input at a time toward extreme values shows which ones move the result most.

How the math works

Future value of monthly annuity at 3%, 5%, 7%.

How to use this beyond the first run

Re-run the calculation once a year. Life changes — pay rises, new expenses, interest-rate shifts — and the figure that looked right 12 months ago often isn't today. Annual recalibration keeps the plan honest.

What this doesn't capture

The calculation assumes a steady savings rate and a stable interest rate. Real saving journeys include emergencies, windfalls, and rate changes — especially in easy-access products. The figure is a direction of travel, not a guarantee.

Related calculations worth running

Plans get firmer when you triangulate. Alongside this one, the compound interest calculator, the wealth building rate calculator, and the drawdown calculator global tend to come up in the same conversations. Running two or three together exposes inconsistencies in any single assumption — which is usually where the useful insight lives.

Worked example

Suppose you save 250 per month for 15 years. The calculator shows three outcomes:

• At 3% annual return: approximately 48,500
• At 5% annual return: approximately 54,900
• At 7% annual return: approximately 62,200

The difference between the 3% and 7% scenario is roughly 13,700 — illustrating how return rate compounds alongside your contributions over time. Your total out-of-pocket savings would be 45,000 (250 × 12 × 15); the remainder comes from accumulated returns at each rate.

When this metric matters

This calculation is most useful when:

• Planning a savings goal over 5–30 years and exploring how different product returns affect the outcome
• Comparing a deposit account (typically lower return) against a stocks-and-shares account (typically higher, more variable return)
• Deciding whether a modest monthly contribution is realistic, or if a higher amount is needed to reach a target
• Stress-testing a plan: seeing what happens at 3%, 5%, and 7% helps frame the range of plausible outcomes

What the result captures and what it doesn't

It shows: projected ending balance at each return rate, assuming contributions remain level and rates remain constant. It models growth in isolation, allowing direct comparison across return scenarios.

It does not show: tax on interest or investment gains, fees or charges, the effect of inflation on purchasing power, volatility or drawdown risk, gaps in savings (maternity leave, job change), or changes in interest rates partway through the period. It is an illustration, not a forecast.

Educational use

This calculator models savings growth for educational purposes. The result estimates what could happen under stable conditions; actual outcomes depend on product choice, market conditions, and behaviour over time. Use it to understand the relationship between monthly savings, time horizon, and return rate — not as a prediction of personal results.