Rent Increase Percentage Calculator
Short answer
This page calculates the percentage only — not whether an increase is legal. Example: $1,800 to $1,950 = a $150 increase, which is 8.33% ($150 ÷ $1,800 × 100). For legality, check caps, notice, and local rules with the Rent Increase Cap Checker for CA and WA.
Last verified: 2026-10-25. This is general information, not legal advice. City ordinances may be stricter and may override state rules. Check the official source for your city and state before acting.
Landlords, tenants, and notices all talk about rent increases in percentages, but the percentage alone says nothing about legality. This calculator does one job — the arithmetic — and points you to the Cap Checker for the legal question. Do not use this page to decide whether an increase is allowed.
This is general information, not legal advice. City ordinances may be stricter and may override state rules. Check the official source for your city and state before acting.
Calculate a rent increase percentage
Formula
Dollar change: new rent − old rent. Percentage change: (new rent − old rent) ÷ old rent × 100%.
Worked example
Old rent $1,800, new rent $1,950. Dollar change: $1,950 − $1,800 = $150. Percentage change: $150 ÷ $1,800 × 100 = 8.33%. Whether an 8.33% increase is lawful is a separate question for the Cap Checker and the official source — this page only establishes that the increase is 8.33%.
Limitations
- This page performs no legality check. Caps (CA, WA), exemptions, notice periods, lease terms, and city ordinances can all affect whether an increase is lawful.
- A percentage based on a wrong old rent is wrong: use the rent actually in force before the increase, not a listed or advertised figure.
- For the legality check, use the Rent Increase Cap Checker; for other states, check the official source.
Sources
- Verified caps cited for cross-reference only: CA AB 1482 cap min(5% + CPI, 10%); WA HB 1217 / RCW 59.18.700 cap min(7% + CPI, 10%) with no increase in the first 12 months. The cap check itself lives on the Rent Increase Cap Checker.
- For the legal background, see Is My Rent Increase Legal? and Rent Rules Explained.
Last verified: 2026-10-25.
Next step: check legality with the Rent Increase Cap Checker, or read Is My Rent Increase Legal?.
Frequently asked questions
Is an 8% increase automatically legal?
No. The percentage is math; legality depends on caps, exemptions, notice, and local rules. An increase within a cap can still fail on notice, and an increase above a cap is not saved by being a small percentage.
How is this different from the Rent Increase Cap Checker?
This page calculates the percentage only. The Cap Checker compares a proposed increase against verified state caps and returns Allowed, Capped, or Check official source.
What if rent went down?
The same formula gives a negative percentage — a decrease. The calculator labels it as a decrease rather than an increase.