Nitro ToolzCompound Interest & Savings Goal Calculator
Project growth with contributions, or solve the monthly amount for a goal.
Compound Interest & Savings Goal Calculator
Generated 10/9/2026
- Mode: Project my balance
- Starting balance: 5000
- Monthly contribution: 400
- Annual interest rate: 5
- Time horizon: 15
- Compounding: Monthly
- Ending balance
- $117,484
- Total contributed
- $77,000
- Interest earned
- $40,484
- Interest share of balance
- 34.5%
Chart loads when visible.
How to use this tool
- Pick whether to project a balance or solve for a goal.
- Enter starting balance, rate, years and compounding frequency.
- Read the ending balance, interest earned and the growth chart.
Formulas
Monthly rate i = (1 + r/m)^(m/12) - 1. Balance = balance x (1 + i) + contribution each month.
Goal mode: contribution = (goal - start x g) / ((g - 1) / i), with g = (1 + i)^n. At 0%, contribution = (goal - start) / n.
Frequently asked questions
How often should interest compound?
Use what your account states. Savings accounts are usually daily or monthly; the difference is small at low rates.
Are contributions made at month end?
Yes, each deposit is added after that month interest.
Does it account for inflation or taxes?
No. Subtract expected inflation from the rate to see growth in today dollars.
What if the rate is 0%?
The result is simply your start plus contributions. The goal solver divides the gap evenly.