Use this reference to identify the right finance formula before entering numbers in a calculator. Each formula is a simplified planning model and should be checked against official terms.
Loan payment
A fixed loan payment uses principal, periodic interest and the number of payments. The payment is level, but the interest and principal portions change over time.
Return and margin
Simple return compares the change in value with the starting value. Margin compares gross profit with revenue. Use matching periods and currencies for both calculations.
Planning checklist
Write down the source and date of each input. Include fees, tax, insurance and inflation when they affect the decision. Treat a calculator result as an estimate until verified by the relevant provider.
- Use consistent units.
- Keep assumptions visible.
- Save the scenario you want to compare later.
Frequently asked questions
Which finance calculator should I start with?
Start with the calculator that matches the decision: loan payment for borrowing, mortgage for home financing, investment for growth and margin for business pricing.