Savings Calculator (Monthly Contributions)

What a starting amount plus a fixed monthly deposit grows to with compound returns — future value, total contributions and earnings.

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Regular Saving, Compounded

The future value combines two parts: your starting amount growing at P·(1+i)ⁿ, and the stream of monthly deposits growing at A·[((1+i)ⁿ − 1) ÷ i] — where i is the monthly rate (annual ÷ 12) and n the number of months. Deposits are assumed at each month's end.

The lesson hidden in the math: time beats amount. At 8% annual, $500/month becomes ≈ $91k in 10 years but ≈ $745k in 30 — the later decades contribute far more than the early ones. Start small, start now. Enter the rate as a nominal annual figure; for an inflation-adjusted answer, use a real return (nominal − inflation).

Frequently Asked Questions

What return rate should I assume?

Long-run broad stock index averages are often quoted near 7-10% nominal; savings accounts and bonds much less. Use a conservative figure for planning, and remember returns are not guaranteed or linear.

Does it account for inflation?

Only if you enter a real (inflation-adjusted) rate. With 9% nominal returns and 4% inflation, enter ~5% to see the answer in today's purchasing power.

Deposit at start or end of month?

The formula assumes end of month. Depositing at the start earns one extra month per deposit — multiply the deposit part by (1+i) for that variant; the difference is small at typical rates.

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