Finance category
Mortgage, loan, investing, tax, and money calculators.
Tax Proration Calculator
Property tax is the biggest prorated item at closing. Each party pays for the days they owned the property. Rules vary by state — arrears-billing states like Illinois and Pennsylvania differ dramatically from prepaid states.
Seller's share
$3,437
days seller owned × per-day rate
Buyer's share
$2,963
Per-day tax
$17.53
Arrears credit to buyer
$0
if paid in arrears
Days in seller's period
196
How the math works
Property tax is prorated so each party pays for the days they owned the property. In prepaid states (tax paid at start of year), the seller gets credit for the unused portion. In arrears states (tax paid at end of year), the buyer gets credit for the seller's portion of the upcoming bill.
States vary: Illinois and Pennsylvania pay in arrears — sellers credit the buyer. California uses fiscal year (July 1). Some jurisdictions use 30/360 day-count banking convention; others use actual days. Title company handles the math — this tool helps you verify.
How to Use
- Enter the annual property tax.
- Pick billing cycle: calendar year, fiscal year (CA July), or arrears (IL, PA, OH).
- Enter the closing day and month.
- Pick day-count convention. Most states use actual days; some use 30/360.
Frequently Asked Questions
Why does billing cycle matter?
If tax is paid at the start of the year (prepaid), the seller's portion is a credit to the seller (they already paid). If it's paid at the end (arrears), the seller's portion is a credit to the buyer (they'll owe it later).
What's the fiscal year in California?
California's property tax fiscal year runs July 1 to June 30. First installment (July-Dec) is due Nov 1, second (Jan-June) due Feb 1. Proration reflects the fiscal year, not calendar year.
What about supplemental tax?
California reassesses at sale, generating a supplemental bill for the difference between old and new assessed values. This is NOT prorated at closing — the buyer pays it for the portion they own.
Which day-count convention should I use?
Most closings use actual days (365). A few use 30/360 (banker's year). Your title company's standard practice determines which; verify by reviewing the Closing Disclosure proration line.
Related Calculators
Property Tax Calculator
Size annual property tax.
Insurance Proration Calculator
Prorate prepaid insurance.
Supplemental Property Tax Calculator
California reassessment at sale.
Escrow Calculator
Monthly escrow funding.
Closing Cost Calculator
Full closing cost picture.
Seller Net Sheet Calculator
Seller-side with proration credits.
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