How to Total Loan Interest Over a Period with CUMIPMT in Excel

Add up a student loan’s interest for any year or the whole term, and work out the tax-deductible amount.

You will learn to

• Total the interest paid in one year
• Total the interest over the life of a loan
• Apply a deduction cap with MIN

How it works

CUMIPMT(rate, nper, pv, start_period, end_period, type) adds up the interest paid from one payment number to another. For the first year of a monthly loan use periods 1 to 12; for year 3 use 25 to 36. All six arguments are required, and pv must be positive.

CUMIPMT always returns a negative number because interest is money you pay. Put a minus sign in front for a positive figure, and combine it with MIN to apply limits such as the $2,500 US student-loan interest deduction.

=-CUMIPMT(B3/12,B4*12,B2,1,12,0)