Calculators
Every calculator applies the statutory rules under the Housing Act 1988 as amended by the Renters’ Rights Act 2025, runs entirely in your browser, and shows its working so you can check the result. All tools are free with no sign-up. Most landlords and tenants start with the Section 13 rent increase date calculator; new calculators are added regularly as the reforms roll out.
Section 13 Rent Increase Date Calculator
The flagship tool. Enter the date Form 4A will be served, the day rent is due and the date of any previous increase, and get the earliest lawful effective date for the new rent – with the two months’ notice rule, rent period rule and 12-month gap applied together and the binding constraint identified. Includes worked examples and the five date errors that most commonly void notices.
Use the calculator →Tenant Notice to Quit Date Calculator
For tenants ending an assured periodic tenancy. Enter your notice date and the day your rent is due to find the earliest valid date your tenancy can end – the two months’ notice rule and the “end of a rent period” rule applied together, with worked examples.
Use the calculator →Rent Arrears Threshold Checker (Ground 8)
For landlords and tenants. Enter the rent and the current arrears to see whether the mandatory Ground 8 possession threshold is met – three months’ rent, or 13 weeks’ for weekly and fortnightly tenancies – with the four-week notice period, the “met at the hearing too” rule and the universal credit carve-out explained.
Use the checker →Section 13 Notice Validity Checker
For landlords and tenants. Work through the requirements that make or break a Form 4A rent increase – the current prescribed form, the two months’ notice, the rent-due-date rule and the 12-month gap – and get a point-by-point read on whether the notice is valid.
Use the checker →Rent Increase Tribunal Deadline Calculator
For tenants who want to challenge a rent increase. Enter the effective date stated on the Form 4A notice to find the deadline for referring the proposed rent to the First-tier Tribunal – the referral must be made before the increase takes effect.
Use the calculator →While more calculators are in development, our plain-English guides cover the same ground in detail – including how to serve a Section 13 notice step by step, what makes a notice invalid and how tenants challenge a rent increase at the tribunal.