How to use a simple interest calculator

1. Enter principal (the starting amount).
2. Enter an annual rate you want to model (not a live bank or loan quote).
3. Enter time in years (or use year presets).
4. Read interest (I), total amount (A), rate compare table, and year schedule.
5. Optional: note the monthly-compound contrast line to see compounding’s effect on the same inputs.

Example: $10,000 · 5% · 3 years

What it is not

• Not a loan or credit offer
• Not investment advice or a return forecast
• Not fees, taxes, or day-count conventions

How we calculate · Questions

Frequently asked questions

What inputs do I need?

Principal ($), annual rate (%), and time in years. Rate is a sample you type—not a live quote.

Can I share a prefilled link?

Yes—use principal, rate, and years query parameters.

Sources linked above include U.S. government materials (for example CFPB, FDIC, NCUA, BLS, IRS) where noted. Sample math uses only labeled Nestfigure assumptions—not bank quotes, job offers, or personalized advice. Last reviewed: August 9, 2026.