Finance calculator
Estimate future value, interest earned, real purchasing power, and contribution growth in one clear calculator.
Educational estimate only. Actual savings rates, investment returns, taxes, fees, inflation, and market outcomes can vary. Investment returns are not guaranteed.
Essentials only. Switch to Advanced for contribution growth, inflation, fees, tax, and the goal planner.
The money you begin with today. Currency only changes formatting, not the math or any local tax rules.
Your current balance. Use 0 to start from scratch.
Used to label the schedule. Optional.
Money you add on a schedule. Beginning-of-period contributions have slightly more time to compound than end-of-period ones.
Your assumed annual return and how often interest is added. Returns are assumptions, not promises.
APY/EAR already includes compounding; a nominal rate depends on the compounding frequency you choose.
These notes are generated from your inputs to help you read the result. They are not financial advice.
Your contributions do most of the work. In year 1, growth is only about 5% of the balance.
Interest becomes visible. By the midpoint, interest-on-interest is a meaningful slice of each year's gain.
Interest-on-interest dominates. By the final year, growth is about 34% of the whole balance.
Balance growth over time
Starting balance, contributions, and interest stacked to your future value.
| Year | Your money | Growth | Balance |
|---|---|---|---|
| 1 | $16,000 | $919 | $16,919 |
| 2 | $22,000 | $2,339 | $24,339 |
| 3 | $28,000 | $4,294 | $32,294 |
| 4 | $34,000 | $6,825 | $40,825 |
| 5 | $40,000 | $9,973 | $49,973 |
| 6 | $46,000 | $13,782 | $59,782 |
| 7 | $52,000 | $18,299 | $70,299 |
| 8 | $58,000 | $23,578 | $81,578 |
| 9 | $64,000 | $29,671 | $93,671 |
| 10 | $70,000 | $36,639 | $106,639 |
| Year | Your money | Growth | Balance |
|---|---|---|---|
| 1 | $16,000 | $919 | $16,919 |
| 2 | $22,000 | $2,339 | $24,339 |
| 3 | $28,000 | $4,294 | $32,294 |
| 4 | $34,000 | $6,825 | $40,825 |
| 5 | $40,000 | $9,973 | $49,973 |
| 6 | $46,000 | $13,782 | $59,782 |
| 7 | $52,000 | $18,299 | $70,299 |
| 8 | $58,000 | $23,578 | $81,578 |
| 9 | $64,000 | $29,671 | $93,671 |
| 10 | $70,000 | $36,639 | $106,639 |
Your money vs growth
How much of the final balance you put in vs what interest added.
| Part | Amount |
|---|---|
| Your money | $70,000 |
| Interest / growth | $36,639 |
| Part | Amount |
|---|---|
| Your money | $70,000 |
| Interest / growth | $36,639 |
Simple vs compound interest
The gap is the value created by interest earning interest.
| Year | Compound | Simple |
|---|---|---|
| Y1 | $16,919 | $16,893 |
| Y2 | $24,339 | $24,205 |
| Y3 | $32,294 | $31,938 |
| Y4 | $40,825 | $40,090 |
| Y5 | $49,973 | $48,663 |
| Y6 | $59,782 | $57,655 |
| Y7 | $70,299 | $67,068 |
| Y8 | $81,578 | $76,900 |
| Y9 | $93,671 | $87,153 |
| Y10 | $106,639 | $97,825 |
| Year | Compound | Simple |
|---|---|---|
| Y1 | $16,919 | $16,893 |
| Y2 | $24,339 | $24,205 |
| Y3 | $32,294 | $31,938 |
| Y4 | $40,825 | $40,090 |
| Y5 | $49,973 | $48,663 |
| Y6 | $59,782 | $57,655 |
| Y7 | $70,299 | $67,068 |
| Y8 | $81,578 | $76,900 |
| Y9 | $93,671 | $87,153 |
| Y10 | $106,639 | $97,825 |
Nominal vs real value
Real value shows today's purchasing power after inflation.
| Year | Nominal | Real |
|---|---|---|
| Y1 | $16,919 | $16,426 |
| Y2 | $24,339 | $22,941 |
| Y3 | $32,294 | $29,554 |
| Y4 | $40,825 | $36,273 |
| Y5 | $49,973 | $43,107 |
| Y6 | $59,782 | $50,066 |
| Y7 | $70,299 | $57,160 |
| Y8 | $81,578 | $64,398 |
| Y9 | $93,671 | $71,791 |
| Y10 | $106,639 | $79,349 |
| Year | Nominal | Real |
|---|---|---|
| Y1 | $16,919 | $16,426 |
| Y2 | $24,339 | $22,941 |
| Y3 | $32,294 | $29,554 |
| Y4 | $40,825 | $36,273 |
| Y5 | $49,973 | $43,107 |
| Y6 | $59,782 | $50,066 |
| Y7 | $70,299 | $57,160 |
| Y8 | $81,578 | $64,398 |
| Y9 | $93,671 | $71,791 |
| Y10 | $106,639 | $79,349 |
Compounding frequency comparison
Same money and rate — only how often interest is added changes.
| Frequency | APY | Final value |
|---|---|---|
| Annually | 7.00% | $105,197 |
| Semi-annually | 7.12% | $105,966 |
| Quarterly | 7.19% | $106,366 |
| Monthly | 7.23% | $106,639 |
| Daily | 7.25% | $106,773 |
| Continuous | 7.25% | $106,777 |
| Frequency | APY | Final value |
|---|---|---|
| Annually | 7.00% | $105,197 |
| Semi-annually | 7.12% | $105,966 |
| Quarterly | 7.19% | $106,366 |
| Monthly | 7.23% | $106,639 |
| Daily | 7.25% | $106,773 |
| Continuous | 7.25% | $106,777 |
Scenario comparison
Final value under different assumptions (set them below).
| Scenario | Final value |
|---|---|
| Base case | $106,639 |
| Lower return (-2%) | $94,111 |
| Higher contribution (+50%) | $149,910 |
| Longer horizon (+10y) | $300,851 |
| Scenario | Final value |
|---|---|
| Base case | $106,639 |
| Lower return (-2%) | $94,111 |
| Higher contribution (+50%) | $149,910 |
| Longer horizon (+10y) | $300,851 |
Best lever for your numbers: 5 more years adds about $80,332 — more than 20% more contribution ($17,308) or 1% higher return ($7,030). Compared over the same horizon.
| Scenario | Final value | Real value | Total contributed | Growth | Fees | Tax | Difference vs base |
|---|---|---|---|---|---|---|---|
| Base case | $106,639 | $79,349 | $70,000 | $36,639 | — | — | — |
| Lower return (-2%) | $94,111 | $70,028 | $70,000 | $24,111 | — | — | -$12,528 |
| Higher contribution (+50%) | $149,910 | $111,547 | $100,000 | $49,910 | — | — | +$43,271 |
| Longer horizon (+10y) | $300,851 | $166,574 | $130,000 | $170,851 | — | — | +$194,212 |
Add an annual fee above to compare fee drag as an extra scenario.
Scenarios are descriptive comparisons, not recommendations. None is labelled good or bad.
| Year | Start | Contributions | Interest/growth | Ending balance | Real value | Growth share |
|---|---|---|---|---|---|---|
| 1 | $10,000 | $6,000 | $919 | $16,919 | $16,426 | 5% |
| 2 | $16,919 | $6,000 | $1,419 | $24,339 | $22,941 | 10% |
| 3 | $24,339 | $6,000 | $1,956 | $32,294 | $29,554 | 13% |
| 4 | $32,294 | $6,000 | $2,531 | $40,825 | $36,273 | 17% |
| 5 | $40,825 | $6,000 | $3,148 | $49,973 | $43,107 | 20% |
| 6 | $49,973 | $6,000 | $3,809 | $59,782 | $50,066 | 23% |
| 7 | $59,782 | $6,000 | $4,518 | $70,299 | $57,160 | 26% |
| 8 | $70,299 | $6,000 | $5,278 | $81,578 | $64,398 | 29% |
| 9 | $81,578 | $6,000 | $6,094 | $93,671 | $71,791 | 32% |
| 10 | $93,671 | $6,000 | $6,968 | $106,639 | $79,349 | 34% |
Work out future value and compound growth from a starting balance and regular monthly or annual contributions, then layer on compounding frequency, inflation, fees, and taxes to see the inflation-adjusted, after-cost result. Switch on goal planning to solve for the contribution, return, time, or starting amount a target needs. Charts, a year-by-year schedule, and a downloadable Excel model are included. Returns are estimates, not promises.
Best for: Savings growth, Retirement planning, Long-term savings projections, Goal planning
Updated June 2026 · Estimates only, not financial advice.
At a glance
The headline is your estimated future value. Below it, the breakdown separates the money you put in (starting balance plus contributions) from the interest and growth it earned, shows the effective annual rate (APY), the inflation-adjusted real value, total fees and estimated taxes, and how the result compares with plain simple interest. Charts and a year-by-year schedule show how the balance builds, and the Excel model lets you keep the full plan.
A month-by-month schedule drives every figure, so the summary, charts, year table, scenarios, and goal solver always agree.
A $10,000 starting balance with $500 added every month at a 7% annual return, compounded monthly, over 10 years (3% inflation) produces this estimate.
Estimated future value
$106,639
Total contributed (incl. start)
$70,000
Interest / growth earned
$36,639
Effective annual rate (APY)
7.23%
Simple-interest comparison
$97,825
Real value after inflation
$79,349
What changes if the return is different
Same starting balance, contribution, and time horizon — only the assumed annual return changes. Returns are not guaranteed.
Mistake to avoid
Do not compare a nominal future value with today's prices without adjusting for inflation. Here the $106,639 balance is worth about $79,349 in today's money at 3% inflation — roughly a quarter less. Check the inflation-adjusted (real) value before deciding whether a projected balance will actually cover a future goal.
Compound interest is interest earned on both your original principal and the interest already added to the balance. Because each period earns interest on a larger base, the balance can grow faster over time — the effect often called interest-on-interest.
For a lump sum, future value is A = P(1 + r/n)^(n x t), where P is the starting amount, r is the annual rate, n is how many times a year interest compounds, and t is the number of years. When you add regular contributions, each contribution also earns interest from the time it is deposited, so the final balance is your starting amount plus contributions plus the growth on both.
Simple interest is calculated only on the original principal, so it grows in a straight line. Compound interest is calculated on the principal plus previously earned interest, so it grows faster the longer it runs. This calculator shows both side by side, and the gap between them is the value created purely by compounding.
APY (annual percentage yield) and EAR (effective annual rate) both describe the true annual return after compounding is taken into account. EAR = (1 + r/n)^n - 1. A 7% nominal rate compounded monthly is about a 7.23% APY. APY lets you compare accounts or investments that compound at different frequencies on an equal footing.
Market returns vary year to year and can be negative. This tool assumes a constant return that you enter, which is useful for planning but does not predict what any account or investment will actually earn. Treat the result as an estimate, not a promise.
For the full picture, see How Compound Interest Works With Regular Contributions.
Investment disclaimer
Returns are assumptions, not guarantees. Actual results may vary because of market performance, taxes, fees, inflation, and timing. This is an educational projection, not investment advice.
How we calculate · Found an error? email us
Learn more
How Compound Interest Works With Regular Contributions
Compound interest with monthly deposits: a worked 10-year example, the math behind it, and where the estimates break down.
Read the guide