Compound interest
Model balance growth with a constant rate, regular deposits and a chosen compounding frequency.
Your inputs
The editable example is illustrative. Enter your own dimensions, operating data, prices, and fees. Results update as you edit.
Calculations run in your browser. Inputs are not saved or sent to analytics.
Your result
Complete the inputs to see your result.
How it works
- n = 12 (Monthly), 4 (Quarterly), 1 (Annual); r = Nominal annual rate ÷ 100 ÷ n; End of period: B′ = B × (1 + r) + D; Start of period: B′ = (B + D) × (1 + r)
- Worked example: 1000 × 1.1² = 1210; 1000 + 12 × 100 = 2200 (r = 0)
- Supported input limits: Initial principal or balance: 0 ≤ x ≤ 1000000000000; Nominal annual rate: 0 ≤ x ≤ 1000; Whole compounding periods: 1 ≤ x ≤ 1200; Deposit per period: 0 ≤ x ≤ 1000000000000
Assumptions and limitations
Amounts use the selected currency without conversion. Rates, prices, fees and index values are assumptions you supply, not current offers or legal tax rates. Financial simulations retain full period precision and stop at 1200 periods; displayed currency uses its minor units. Taxes, fees and market changes are included only where entered.
Sources
- Investor.gov — compound interest calculator Sources reviewed: 2026-10-06
- Investor.gov — savings goal calculator Sources reviewed: 2026-10-06
- CFPB — compound interest Sources reviewed: 2026-10-06
