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What will a lump sum be worth years from now? Whether it is a $10,000 bonus you plan to invest, an inheritance arriving later, or a bond’s maturity value, the answer depends on compound interest — growth calculated not just on your original sum but on every dollar of growth that came before. This calculator grows any present sum forward in time and splits the result into your original principal and the interest earned, so you can see exactly how much of the future value is your money and how much is compounding’s gift.
Using it takes less than a minute:
Pro tip: the most revealing experiment is changing only the compounding frequency. Run $10,000 at 7% for 10 years annually ($19,671.51), then monthly ($20,096.61), then daily — the gap teaches you what “compounding” really buys, and the effective annual rate line quantifies it in a single number.
The future value (FV) of a present sum is what a single lump of money — the present value (PV) — grows to after compounding for a given time at a given rate. It is the simplest and most fundamental calculation in all of finance: one deposit, one rate, one horizon. Every fancier computation — annuities, loan amortization, bond pricing, retirement planning — is built from this single building block repeated or rearranged.
The engine is compound interest: each period’s interest is calculated on the balance including all previously earned interest, so growth accelerates over time. Contrast this with simple interest, which pays only on the original principal forever. On $10,000 at 7% for 10 years, simple interest earns a flat $700 a year — $7,000 total. Compounding earns $9,671.51, about 38% more, because in later years you earn 7% on a balance swollen by earlier interest. The longer the horizon, the wider the gap becomes — over 30 years, compounding more than doubles simple interest’s result.
Two rate concepts matter here. The nominal (stated) rate is the headline percentage, like 7%. The compounding frequency — how many times per year interest is credited — determines the effective annual rate (EAR), the true yearly growth. At 7% nominal: annual compounding gives an EAR of exactly 7.0000%; monthly compounding gives (1 + 0.07/12)12 − 1 ≈ 7.229%; daily compounding gives about 7.251%. The calculator displays the EAR so you can compare products with different frequencies honestly.
A handy mental shortcut is the Rule of 72: divide 72 by the annual rate to estimate doubling time. At 7%, money doubles in roughly 72 ÷ 7 ≈ 10.3 years — which is why $10,000 at 7% becomes $19,671.51 (just shy of double) in 10 years. At 8%, doubling takes about 9 years; at 5%, about 14.4 years. It is an approximation, but it turns abstract rates into intuitive timelines instantly.
This calculation is everywhere in real financial life: projecting what a lump-sum investment becomes by retirement, pricing what a future payout (a bond, a legal settlement, an inheritance) is worth negotiating over today, comparing two savings products with different rates and frequencies, and sanity-checking any “grow your money” claim you encounter.
The future value of a present sum comes from the compound-interest formula:
FV = PV × (1 + r/m)m×n
Here PV is the present sum, r is the annual interest rate as a decimal, m is the number of compounding periods per year (1 for annual, 4 for quarterly, 12 for monthly, 365 for daily), and n is the number of years. The term r/m is the rate per period, and m×n is the total number of compounding periods. Each period multiplies the balance by (1 + r/m) — compounding in its purest form.
Worked example 1. Invest $10,000 at 7% for 10 years, compounded annually. Here r = 0.07, m = 1, n = 10, so there are 10 periods at 7% each. Compute (1.07)10 ≈ 1.967151. Then FV = $10,000 × 1.967151 ≈ $19,671.51 — exactly the calculator’s result above. The interest earned is $19,671.51 − $10,000 = $9,671.51, and the effective annual rate is 7.0000% since compounding is annual. Step by step, year 1 grows the balance to $10,700, year 2 to $11,449, and by year 10 the annual interest alone ($1,285) exceeds the entire first year’s gain ($700).
Worked example 2. Invest $5,000 at 5% for 10 years, compounded annually. Compute (1.05)10 ≈ 1.628895. Then FV = $5,000 × 1.628895 ≈ $8,144.47, with interest of $3,144.47. Compare with example 1: the rate fell 2 points and the principal halved, yet the growth multiple (1.63× vs 1.97×) shows how sensitive long-run results are to the rate — a 2-point rate difference compounded over a decade changes the outcome by hundreds of dollars on every thousand invested.
For continuous compounding (interest credited every instant), the formula becomes FV = PV × ert — the mathematical limit as m approaches infinity. At 7% for 10 years that gives $10,000 × e0.7 ≈ $20,137.53, only fractionally above daily compounding’s $20,137.50: beyond daily frequency, the gains are negligible, which is why daily is the practical ceiling.
Imagine you receive a $25,000 bonus at age 45 and invest it all in a diversified portfolio averaging 8% annually, compounded quarterly, until age 65 — 20 years of untouched compounding.
In formula terms: r = 0.08, m = 4, n = 20, so the quarterly rate is 0.02 and there are 80 periods. Compute (1.02)80 ≈ 4.87544. Then FV = $25,000 × 4.87544 ≈ $121,886. Your original $25,000 is still in there — and compounding added roughly $96,886, nearly four times your deposit. The effective annual rate is (1.02)4 − 1 ≈ 8.243%, a free 0.24-point boost from quarterly crediting.
Notice the shape of the growth: after 10 years the balance is about $55,200 (only $30,200 of growth), but the second decade adds roughly $66,700 — more than double the first decade’s gain, on the same money, with no additional deposits. That back-loaded explosion is compounding’s signature, and it is why the last years before retirement are the most valuable: every extra year you leave a lump sum invested adds more dollars than any earlier year did.
The planning lesson: lump sums deserve the same respect as monthly contributions. A single $25,000 invested at 45 rivals years of $200 monthly deposits started later. When windfalls arrive — bonuses, inheritances, property sales — investing them promptly rather than letting them sit in cash for “the right moment” is usually worth tens of thousands over a multi-decade horizon.
Take the widget’s baseline — $10,000 at 7% for 10 years — and vary only the compounding frequency:
Two insights fall out. First, moving from annual to monthly compounding is worth real money — $425 on $10,000 over a decade, or over 2% extra — because each month’s interest starts earning its own interest eleven months sooner than under annual crediting. Second, the gains shrink fast: daily beats monthly by only $41, and continuous compounding would add mere cents beyond daily. Frequency matters, but with sharply diminishing returns past monthly.
The far bigger levers remain rate and time. Bumping the rate from 7% to 8% (annual compounding) lifts the result to $21,589 — a $1,918 gain that dwarfs the $425 frequency effect. And extending from 10 to 15 years at 7% reaches $27,590. When comparing real products, rank them by effective annual rate first, time horizon second, and compounding frequency a distant third — and beware any advertisement trumpeting “daily compounding” on a low nominal rate.
1. Using simple interest instead of compound interest. Multiplying principal × rate × years ($10,000 × 7% × 10 = $7,000) understates the true $9,671.51 by 38%. Simple interest applies to some short-term loans and bonds, but investments, savings accounts, and reinvested returns all compound — always use the compounding formula for growth projections.
2. Confusing the nominal rate with the effective annual rate. A “7% account compounded monthly” actually grows at 7.229% per year. When comparing a monthly-compounding account against an annually-compounding one, compare EARs, not nominals — the calculator shows the EAR precisely so you do not have to guess.
3. Ignoring inflation and taxes. A 7% nominal return with 3% inflation is roughly a 4% real return: your $19,671.51 buys what about $14,600 buys today. And in taxable accounts, annual taxes on interest drag compounding down further. Project in real, after-tax terms for honest planning.
4. Forgetting that frequency must match the product. Plugging m = 12 for an account that credits annually overstates growth; using m = 1 for monthly-crediting CDs understates it. Read the account terms — banks disclose compounding frequency — and match it in the calculator.
5. Using this formula for payment streams. The present-sum formula handles one lump sum. If you are making regular deposits, that is an annuity — use the future value of annuity calculation instead, where each payment compounds for its own remaining time. Mixing the two is the most common textbook error.
When your scenario involves multiple deposits or withdrawals rather than a single lump sum, use the Future Value of Cash Flows Calculator, which compounds each cash flow from its own date. For the full toolkit — annuities, loans, mortgages, and more — browse the Financial Calculators collection.
Page summary: This page provides a future value of present sum calculator. Inputs: present value (dollars), annual interest rate (percent), years, compounding frequency (annually, semi-annually, quarterly, monthly, daily). Outputs: future value, present value, interest earned, effective annual rate. Method: FV = PV × (1 + r/m)^(m×n), with r the annual rate as a decimal, m compounding periods per year, n years. Reference figures: $10,000 at 7% for 10 years compounded annually → FV $19,671.51, interest $9,671.51, EAR 7.0000%; same inputs compounded monthly → FV $20,096.61. Scope: single lump sum, fixed nominal rate; excludes inflation, taxes, fees, and additional deposits or withdrawals.
Sources: standard time-value-of-money mathematics as published in finance textbooks and by the U.S. Securities and Exchange Commission’s investor education materials (investor.gov). Worked-example figures were computed with the formulas above and cross-checked against the calculator widget on this page. Figures rounded to the nearest cent; actual results vary with rate changes, fees, and compounding conventions.
Grow any lump sum at compound interest — see the future value and the interest earned, with adjustable compounding frequency.
Multiply the lump sum by (1 + rate per period) raised to the number of periods: FV = PV × (1 + r/m)^(m×n). Try the calculator above.
About $19,671.51 with annual compounding — nearly double, since compound interest adds $9,671.51 on top of your principal.
Yes — monthly compounding on that same $10,000 at 7% reaches $20,096.61 after 10 years, about $425 more than annual compounding.
Simple interest on $10,000 at 7% for 10 years earns $7,000; compounding earns $9,671.51 — because interest earns interest in later years.
Projecting a lump-sum investment, pricing a bond payment, valuing an inheritance received later, or comparing growth across savings products.