Stop Guessing the Math

5% of $1,875? $1,500 ÷ 31 × 17 days? Let the calculator do it. Get exact amounts for late fees, prorated rent, and rent increases.

3 calculators. All free. Instant results.

Calculate late fees based on percentage, flat rate, or daily charges. Get the exact amount your tenant owes.

Percentage feesFlat feesDaily chargesTotal amount due

Calculate prorated rent for mid-month move-ins or move-outs. Calendar or banker's method. No more math errors.

Calendar methodBanker's methodDaily rateFirst full month

Calculate new rent by percentage or fixed amount. See annual impact and check rent control compliance.

Percentage increaseFixed amountAnnual impactRent control check

Why Use These Calculators

No arithmetic errors

$1,800 ÷ 28 × 14 = $900. Not $892.86. Wait, let me check again... Just use the calculator. Get it right the first time.

Industry-standard formulas

Calendar method for proration. Percentage and daily fees for late rent. The same calculations property managers use nationwide.

Instant results

Enter your numbers. See the breakdown immediately. No page loads, no waiting, no email verification.

Rent control warnings

The rent increase calculator warns you if your increase exceeds 10%. Know if you're hitting rent control limits before you send the notice.

100% free. No account required. Use as many times as you need.

You've calculated the amount. Now put it in a proper document. Our templates include the amount due, dates, and required legal language.

Free PDF download. No account required.