What does this interest calculator work out?

The interest calculator works out the total interest and end value on a starting balance over a period you choose, using either simple interest (interest on the principal only) or compound interest (interest on the principal plus previously earned interest). It runs entirely in your browser — no data is sent anywhere.

What is the difference between simple and compound interest?

Simple interest is calculated only on the original principal. Compound interest is calculated on the principal plus any interest already earned, so it grows faster over time. For borrowing, compound interest means the cost rises faster if you carry a balance. For savings, it means your pot grows faster when interest is reinvested.

Interest reckoner

Wirk oot hoo muckle interest a balance earns or costs. Simple interest is chairged anely on the original amoont; compound interest is chairged on the balance includin interest aaready eikit, sae it growes faster.

Interest: —
Hindmaist balance: —

The formulae

Semple interest: I = P × r × t
Compoondit: A = P × (1 + r/n)^n×t

P is the principal, r is the annual rate as a decimal, t is the time in years, an n is the nummer o times interest is eikit ilka year.

Wirkit example

Hold £1,000.00 at 6% a year for 2 years. With simple interest you earn £120.00, giving £1,120.00. Compounding monthly you earn £127.16, giving £1,127.16 — a little more, because each month's interest then earns interest too.

Whaur tae gang neist

Loan affordability sel-check — afore ony borraein decision.
Oor business loan — the coст, the cap an wha can apply.
Help wi peyments — gin siller is ticht, speak tae us early.
MoneyHelper — free, impairtial money guidance backit bi the govrenment.
gov.uk Business Finance Support — grants an finance ye micht be eligible for.