CMPDcompound
Compound Interest Calculator 2026
The most complete compound interest calculator in 2026 — 11 compounding frequencies (Daily 365/360, Semi-weekly, Weekly, Bi-weekly, Semi-monthly, Monthly, Bi-monthly, Quarterly, Semi-annually, Annually), regular deposits + withdrawals, annual deposit increases for real-world raises, side-by-side scenario comparison, and shareable URLs that preserve every input. Multi-currency: USD, EUR, GBP, SGD, INR, AUD, CAD, VND.
Updated: ·See data sources
§ 01
How to use
- Enter starting amount. Money you have today to begin investing.
- Set rate & horizon. Annual % rate and years you plan to hold.
- Add monthly contribution. Optional fixed amount added each month for DCA.
§ 02
Key features
11 compounding modes
From Daily 365/360 to Annually — match any product.
Deposits + withdrawals
Simulate paychecks-in and living-expenses-out at once.
Annual deposit raise
Bump contributions by a % each year for real-world raises.
Compare 2 scenarios
Side-by-side A/B test with instant difference.
Shareable URL
One-click copy preserves every input for sharing.
EAR + time to double
Effective Annual Rate plus years-to-double.
§ 03
Why Treasury.to?
- Free, no aggressive ads
- 5 compounding frequencies
- Year-by-year growth chart
- Includes periodic contributions
- Per-year drilldown table
- Mobile-friendly
§ 04
Frequently asked questions
01What does 10% over 20 years grow to?
$10,000 at 10% compounded monthly grows to about $73,280 after 20 years. Add $200/month and it jumps to roughly $215,000.
02How is compound different from simple interest?
Compound interest earns on prior interest too, so growth is exponential. Simple interest only earns on the original principal — linear growth. The longer the horizon, the larger the gap.
03Which compounding frequency should I pick?
Most savings products compound monthly or quarterly. ETFs and stocks are usually modeled annually. Switch the frequency in the tool to compare outcomes.
04What rate is realistic?
Vietnam savings: 5–7%/year. US stocks historical average: 8–10%/year pre-tax. Use a conservative assumption you can stick with.
05Does it account for inflation?
The current version shows nominal values. Subtract ~3–4% from your input rate to estimate real purchasing power.