Financial Calculator guide
Financial Calculator: Time Value of Money (TVM) Made Easy
Use our free online financial calculator to solve for payment, future value, present value, term or interest rate, with the cash flow sign convention explained.
By the AllCalculator editorial teamUpdated 15 October 20262 min read
Loans, mortgages, savings plans and investments all follow the same maths: the time value of money. A pound today is worth more than a pound in the future, because it can earn interest. Our Financial Calculator solves these problems the same way a dedicated financial calculator does.
The five TVM values
- N: the number of payments.
- I/Y: the interest rate a year.
- PV: the present value, money now.
- PMT: the regular payment each period.
- FV: the future value, money at the end.
Enter any four and the calculator works out the fifth.
The sign convention
Like a financial calculator, money you receive is positive and money you pay out is negative. For a loan, the amount you borrow (PV) is positive and your repayments (PMT) are negative. For savings, your deposit and payments are negative and the final balance (FV) is positive.
How to use the calculator (Financial Calculator)
- Choose what to solve for.
- Enter the other values, minding the signs.
- Set the payments a year and whether payments are at the end or start of each period.
Worked examples
Mortgage payment. With the calculator's default settings, borrowing £200,000 over 300 months at 4.5%, the monthly payment is −£1,111.66.
Savings growth. Investing £10,000 now (PV = −10,000) and £200 a month (PMT = −200) for 10 years at 5% gives an FV of about £47,527.
How long to clear a loan. £200,000 at 4.5% with £1,500 monthly payments takes about 185 months, or 15.4 years.
What rate am I paying? Solve for I/Y with N = 300, PV = 200,000 and PMT = −1,111.66, and you get back 4.5%.
Effective annual rate
Interest charged monthly compounds, so 4.5% a year charged monthly is an effective 4.59%. The calculator shows this as the EAR.
For everyday loans, try our Loan Repayment Calculator, and for mortgages our Mortgage Payment Calculator.
Frequently asked questions
Why is my payment negative?
It's money you pay out. That's the standard sign convention.
Why can't the calculator find an interest rate?
Usually the signs are wrong. There must be at least one positive and one negative cash flow.
What does BGN mean?
Payments at the beginning of each period, as with rent or leases. Most loans are paid at the end.
Use the Financial Calculator for coursework, exams practice and real-life money decisions.
Sources and further reading
- CFA Institute: Time value of moneycfainstitute.org
- MoneyHelper: Understanding interest ratesmoneyhelper.org.uk
Links open official and independent websites in a new tab.
This guide is general information to help you understand your options. It isn't financial, tax, legal or building advice and doesn't take your personal circumstances into account. Figures were checked when the guide was last updated and can change, so confirm anything important with GOV.UK, HMRC, a regulated adviser or a qualified tradesperson.