Price a lease addendum correctly before you send it
Enter the current lease and proposed changes — we compute the new monthly total, fee stacking, and whether your state's notice rules are met.
Enter the current lease
Today's rent and any existing monthly fees.
Add the proposed changes
Rent increase, pet rent, utility or parking fees.
Check the new total
New monthly amount plus your state's cap and notice rules.
Lease Addendum Calculator
Rent-change caps and notice periods vary by state — some changes need 30, 60, or 90 days' written notice. We flag yours.
Your result
Your new monthly total is ready. Email unlocks the compliance check and tenant-ready addendum.
Your total above is free. The locked rows are the compliance extras.
Unlock your full addendum analysis
Get the compliance check, 12-month projection, and a tenant-ready addendum template you can fill in.
Your compliance check
The Landlord's Addendum Pack
Every addendum you'll ever need to serve — attorney-drafted, state-aware, ready to send.
- 15 attorney-drafted addendum templates (pet, rent change, roommate, utilities)
- 50-state rent-cap & notice-period cheat sheet
- Fee-stacking compliance checklist
- Tenant notice letter templates
Lease addendum questions
How much notice do I need before a rent change?
Most states require 30 days' written notice for month-to-month leases; some (like California for larger increases) require 60 or 90 days. Fixed-term leases generally can't change mid-term without tenant agreement.
Can I add pet rent to an existing lease mid-term?
Not unilaterally — a pet rent addendum needs the tenant's signature. Mid-lease changes are negotiations, not notices. The email unlock includes a consent-ready template.
Is there a cap on how much I can raise rent?
About ten states (and many cities) cap rent increases or ban them during a tenancy. The compliance check flags your state’s rules against the numbers you entered.
Do fees count toward rent-increase caps?
In some jurisdictions, new recurring fees are treated as rent for cap purposes. This is exactly the fee-stacking issue the calculator checks.