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.

Cyfrifiannell llog

Cyfrifwch faint o log y mae balans yn ei ennill neu'n ei gostio. Codir llog syml ar y swm gwreiddiol yn unig; codir llog cyfansawdd ar y balans gan gynnwys llog sydd eisoes wedi'i ychwanegu, felly mae'n tyfu'n gyflymach.

Amount (£) Annual interest rate (%) Amser (blynyddoedd) Math o log

Llog: —
Balans terfynol: —

Y fformiwlâu

Llog syml: I = P × r × t
Cyfansawdd: A = P × (1 + r/n)^n×t

P yw'r prifswm, r yw'r gyfradd flynyddol fel degolyn, t yw'r amser mewn blynyddoedd, ac n yw'r nifer o weithiau y caiff llog ei ychwanegu bob blwyddyn.

Enghraifft wedi'i gweithio

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.

Ble i fynd nesaf

Hunan-wiriad fforddiadwyedd benthyciad — cyn unrhyw benderfyniad benthyca.
Ein benthyciad busnes — y gost, y cap a phwy all ymgeisio.
Help gyda thaliadau — os yw arian yn dynn, siaradwch â ni'n gynnar.
MoneyHelper — arweiniad ariannol rhad ac am ddim, diduedd, gyda chefnogaeth y llywodraeth.
gov.uk Business Finance Support — grantiau a chyllid y gallech fod yn gymwys ar eu cyfer.