How to use the prepaid expense amortization calculator
- Enter the amount paid in advance and the months covered, from 1 to 120.
- Pick the date the coverage starts. Only the month matters, and the first month is counted as a full month.
- Read the headline for the monthly expense, then the table by calendar year for each year's expense and the balance still prepaid at year end.
- For terms of 36 months or fewer, the month-by-month table shows every month. The CSV download always has every month.
Formula
monthly expense = cost / months, rounded to the cent (half up)
last month = the balance left, so the total equals the cost exactly
prepaid balance after a month = balance before - expense
All amounts are held in whole cents. Rounding the monthly amount can leave a few cents over or short after the last month, so the final month takes the difference.
A $2,400 policy over 12 months
$2,400 / 12 months is exactly $200.00 a month. Starting in January 2026, the 12 months all fall in 2026, so the expense that year is $2,400 and nothing is left prepaid at year end.
Starting in July instead, 6 months ($1,200) fall in 2026 with $1,200 still prepaid at December 31, and the other 6 months fall in 2027. Uneven amounts: $1,000 over 3 months is $333.33, $333.33 and $333.34, and $1,234.57 over 7 months from November is $176.37 six times and $176.35 in the last month.
Why spread a prepaid cost
When you pay for insurance, rent or a subscription up front, the benefit arrives over time. Accounting that follows the matching idea records the payment as an asset first and moves a slice of it to expense each month the coverage is used. The schedule shows the monthly slice and what is still sitting on the books as an asset.
The yearly table is the one to use when a policy crosses a year end, because only the months in each year are expensed in that year. For the entries themselves, see the Journal Entry Generator and the Chart of Accounts Template.
Limits of a simple schedule
This is straight-line with whole months. It does not prorate a partial first month, handle a cancellation refund, or follow a policy of expensing small items at once. What counts as a prepaid asset, and how, is a decision for your accountant and your accounting policy. Related: the Depreciation Calculator spreads the cost of equipment, which works differently.
Assumptions and limits
- Straight-line, in whole months, with the first month counted in full and the day of the month ignored.
- The last month absorbs the rounding difference, so the schedule adds up to the cost exactly.
- The amount may have up to two decimals and the term runs from 1 to 120 months.
- This is arithmetic, not accounting or tax advice.
Frequently asked questions
How do you amortize a prepaid expense?
Divide the amount paid by the number of months it covers and record that much as expense each month. A $2,400 annual insurance premium is $200 a month. The balance still prepaid falls by that amount until it reaches zero.
What happens to the odd cents?
The monthly amount is rounded to the cent, and any difference is put in the last month, so the schedule adds up to the exact amount paid. $1,000 over 3 months is $333.33, $333.33 and $333.34.
How much of a prepaid cost is expensed in the first year?
Only the months that fall in that calendar year. A 12 month policy starting in July has 6 months in the first year, so half the cost is expensed that year and half the following year. The yearly table shows this.
Can I get the whole schedule as a file?
Yes. The CSV download lists every month with its expense and the prepaid balance, even for terms longer than 36 months, where the page shows the yearly table only to keep the page readable.