US Rent Tools

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Methodology

This page explains exactly how US Rent Tools calculates its results, which rules it uses, where those rules come from, how they are tested, and what the site does not cover. If a rule is not listed here as verified, this site does not use it — for all other states and rules, the answer is “Check official source.”

Formulas

  • Prorated rent, actual-days: monthly rent ÷ days in the month × days occupied.
  • Prorated rent, 30-day: monthly rent ÷ 30 × days occupied.
  • Prorated rent, 365-day: monthly rent × 12 ÷ 365 × days occupied.
  • California rent cap (AB 1482, Civil Code 1947.12): maximum increase = min(5% + local CPI, 10%) per 12 months, for covered properties.
  • Washington rent cap (HB 1217, RCW 59.18.700): maximum increase = min(7% + CPI, 10%); no increase in the first 12 months.
  • California deposit (AB 12, Civil Code 1950.5): generally 1 month’s rent; small-landlord exception 2 months; return within 21 calendar days.
  • Texas deposit (Property Code 92.103, 92.107): no statutory cap on amount; return within 30 days, with the forwarding-address trigger.
  • Oregon late fee (ORS 90.260): 4-day grace period; fee must be in a written agreement; 5% per succeeding 5-day period is one statutory structure — not a single flat 5% overall cap.

Verified sources

These sources are the basis for the verified rules on this site. Where a source is a summary rather than the statute itself, the statute cited (for example Civil Code 1947.12 or ORS 90.260) is the controlling reference, and users should check the statute and their city ordinance before acting.

Test cases

  • Prorated rent: $1,800 rent, move-in 16 October, 31-day month, actual-days method = $1,800 ÷ 31 × 16 = $929.03.
  • California rent cap: $2,000 rent + 3% CPI = 5% + 3% = 8%, below the 10% ceiling, so maximum rent = $2,000 × 1.08 = $2,160.
  • Texas deposit deadline: move-out + forwarding address + 30 days. For example, move-out and forwarding address given on 1 October gives a deadline of 31 October, subject to the trigger as described in Property Code 92.103 and 92.107.

Calculators are checked against these test cases before any change is published. A calculator that fails a test case is not published until it passes.

Update cadence

State rules on this site are reviewed quarterly and after known law changes. When a law changes, the affected calculator, guide, and this methodology page are updated together, and the last-updated date on the page is changed. Until an update is verified, the previous verified rule remains shown with its last-verified date, rather than being replaced by an unverified summary.

What is NOT covered

  • All unlisted states: for any state without a verified rule on this page, this site does not state a cap, deadline, or limit — check the official source.
  • Local ordinances: city and county rules may be stricter and may override state rules. They are not exhaustively covered here.
  • Interest rules on deposits, and other deposit-related rules not listed above.
  • Coverage, exemptions, notice validity, and enforcement procedure for any individual case — these require checking the official source and, where needed, qualified advice.

Last verified for state rules: 2026-10-25.

Last updated: 2026-10-25. Last verified for state rules: 2026-10-25.