Late Fee Calculator

Calculate the late fee owed using flat amount, percentage, or per-day method. Includes state-cap warnings.

How late fees work

A late fee is a charge added to overdue rent. To enforce it, the fee must be (1) clearly stated in the written lease, (2) within your state's legal limit, and (3) generally considered “reasonable” by a court.

Three common structures

Flat fee: A fixed dollar amount, like $50 or $75. Easiest to administer.

Percentage: A percent of monthly rent. 5% is common and stays within most state caps.

Per-day: A daily amount that accrues until paid (e.g. $10/day). Make sure it stops at a reasonable max — courts can void runaway daily fees.

State caps to know

New York and Colorado cap fees at $50 or 5% of rent, whichever is less. Iowa caps at $12/day or $60/month for low-rent units. Most other states use a “reasonableness” standard. See state landlord laws for the full list.