Is the Compound Interest Calculator free?

Yes — the Compound Interest Calculator is completely free, with no account, subscription, signup, or usage limits.

Is my data uploaded or stored?

No. The Compound Interest Calculator processes everything locally in your browser. Your input is never uploaded, saved, or shared with any server.

Does the Compound Interest Calculator work offline?

Yes. Once the page has finished loading, the Compound Interest Calculator works without an internet connection.

Which browsers does the Compound Interest Calculator work in?

The Compound Interest Calculator works in all modern browsers, including Chrome, Firefox, Safari, and Edge — no plugins or extensions needed.

What is the difference between simple interest and compound interest?

Simple interest is calculated only on the original principal each period. Compound interest is calculated on the principal plus any interest already accumulated — so each period's interest is larger than the last. Over long periods, the difference is dramatic. $10,000 at 8% simple interest for 20 years gives $26,000. At 8% compound interest (monthly) it gives over $49,000.

How often should interest compound to maximise growth?

More frequent compounding produces slightly higher returns. Daily compounding earns marginally more than monthly, which earns more than annual. In practice, the difference between daily and monthly compounding is small — the rate and time period matter far more. Most savings accounts compound monthly or daily.

Does this calculator account for inflation?

No — it shows nominal growth. To estimate real (inflation-adjusted) returns, subtract the expected inflation rate from your interest rate. For example, if the interest rate is 8% and inflation is 3%, use 5% as the "real" rate to see purchasing-power growth.

Compound Interest Calculator

Calculate compound interest growth for savings and investments with a year-by-year breakdown.

Initial Principal

Annual Interest Rate (%)

Compounding Frequency

Duration (Years)

Monthly Contribution ($)

Final Balance

$20,096.61

Total Contributed

$10,000.00

Interest Earned

$10,096.61

Year	Balance	Total Contributed	Interest Earned
Year 1	$10,722.90	$10,000.00	$722.90
Year 2	$11,498.06	$10,000.00	$1,498.06
Year 3	$12,329.26	$10,000.00	$2,329.26
Year 4	$13,220.54	$10,000.00	$3,220.54
Year 5	$14,176.25	$10,000.00	$4,176.25
Year 6	$15,201.06	$10,000.00	$5,201.06
Year 7	$16,299.94	$10,000.00	$6,299.94
Year 8	$17,478.26	$10,000.00	$7,478.26
Year 9	$18,741.77	$10,000.00	$8,741.77
Year 10	$20,096.61	$10,000.00	$10,096.61

Free browser-based tool · Runs 100% on your device · Last updated July 7, 2026

What is the Compound Interest Calculator?

The free Compound Interest Calculator shows you exactly how money grows over time when interest is earned on both the original principal and the interest already accumulated. Enter your starting amount, annual interest rate, compounding frequency, investment period, and optional monthly contributions — and the tool instantly shows your final balance, total interest earned, and a year-by-year growth table so you can see the power of compounding play out row by row.

→ Plan a savings goal — find out how much a lump sum grows over 5, 10, or 20 years
→ Model the impact of regular monthly contributions on long-term investment growth
→ Compare weekly, monthly, and annual compounding to see how frequency affects returns
→ Estimate a retirement nest egg based on current savings and expected returns
→ Show students or clients the "snowball effect" of interest compounding on interest

How to Use the Compound Interest Calculator

1 Enter your Starting Principal — the initial amount you are investing or saving.
2 Set the Annual Interest Rate (%) — for example, 8% for a typical equity-linked savings account.
3 Choose how often interest compounds using the Compounding Frequency dropdown (daily, monthly, quarterly, annually).
4 Enter the Investment Period in years.
5 Optionally add a Monthly Contribution to model regular deposits.
6 Read the results: Final Balance, Total Interest Earned, and the year-by-year table showing balance growth.

Key Features

📈
Year-by-year table

See your balance, contributions, and interest earned for every year of the investment.
💳
Monthly contributions

Model regular deposits alongside a starting lump sum for realistic savings plans.
🔄
Multiple frequencies

Compare daily, monthly, quarterly, and annual compounding side by side.
🆓
Free, no signup

Completely free — no account, no data sent to any server.

Example Usage

Example Input

Principal: $10,000 | Rate: 8% p.a. | Compounding: Monthly | Period: 10 years | Monthly contribution: $200

Example Output

Final Balance:         $50,970.77
Total Contributions:   $34,000.00
Total Interest Earned: $16,970.77

Frequently Asked Questions about the Compound Interest Calculator

What is the Compound Interest Calculator?: The Compound Interest Calculator is a free online tool that lets you calculate compound interest growth for savings and investments with a year-by-year breakdown. It runs entirely in your browser, so there is nothing to install and nothing is uploaded to a server.
Is the Compound Interest Calculator free?: Yes — the Compound Interest Calculator is completely free, with no account, subscription, signup, or usage limits.
Is my data uploaded or stored?: No. The Compound Interest Calculator processes everything locally in your browser. Your input is never uploaded, saved, or shared with any server.
Does the Compound Interest Calculator work offline?: Yes. Once the page has finished loading, the Compound Interest Calculator works without an internet connection.
Which browsers does the Compound Interest Calculator work in?: The Compound Interest Calculator works in all modern browsers, including Chrome, Firefox, Safari, and Edge — no plugins or extensions needed.
What is the difference between simple interest and compound interest?: Simple interest is calculated only on the original principal each period. Compound interest is calculated on the principal plus any interest already accumulated — so each period's interest is larger than the last. Over long periods, the difference is dramatic. $10,000 at 8% simple interest for 20 years gives $26,000. At 8% compound interest (monthly) it gives over $49,000.
How often should interest compound to maximise growth?: More frequent compounding produces slightly higher returns. Daily compounding earns marginally more than monthly, which earns more than annual. In practice, the difference between daily and monthly compounding is small — the rate and time period matter far more. Most savings accounts compound monthly or daily.
Does this calculator account for inflation?: No — it shows nominal growth. To estimate real (inflation-adjusted) returns, subtract the expected inflation rate from your interest rate. For example, if the interest rate is 8% and inflation is 3%, use 5% as the "real" rate to see purchasing-power growth.