Simple interest calculator

Calculate interest and total amount over years, months or days.

Runs on your deviceWorks offline after setupAll Business tools

Related tools

Enter your values, then choose Calculate. Results stay on this device.

Limits
  • Simple interest, without compounding, taxes or fees. Principal accepts 2 decimals; rate and time accept 4. Days use a fixed 365-day year. Up to 1,000 years and 1,000% annual interest; estimates round half away from zero to 2 decimals.
  • The math runs on this device. It is an estimate, not financial or medical advice.
  • Desktop limits are provisional. Physical mobile and Safari verification remains open.

What happens to your data

Simple interest calculator runs inside this browser tab, and the page's code comes from this site. There is no application server to receive your data, and the site's security policy limits connections to this site.

How local processing works

Good to know

  • Simple interest, without compounding, taxes or fees. Principal accepts 2 decimals; rate and time accept 4. Days use a fixed 365-day year. Up to 1,000 years and 1,000% annual interest; estimates round half away from zero to 2 decimals.
  • The math runs on this device. It is an estimate, not financial or medical advice.
  • Desktop limits are provisional. Physical mobile and Safari verification remains open.