Landlord Calculator

Late Fee Calculator

Work out a late fee as a flat amount or a percentage of rent, whichever your lease specifies, then check it against your state's legal limits.

▶ Run the Calculator

Opens live in the Rental Flow app, no account needed.

What this calculator does

Most leases specify a late fee as either a flat dollar amount or a percentage of monthly rent. This calculator computes either method so you can see the dollar impact before applying it to an overdue payment.

The formula

Late Fee = a flat dollar amount, or Monthly Rent × Late Fee Percentage

Important: many states cap late fees by law, some as a flat maximum, others as a percentage of rent, and some require a grace period before any fee applies. Always check your state and local regulations before charging a late fee; this calculator does not apply any legal caps.

Worked example

$1,500/month rent, 5% late fee

Monthly rent$1,500
Late fee percentage5%
Late fee$75

A 5% late fee on $1,500 rent comes to $75, the same dollar amount a flat $75 fee would charge in this example.

How much can a landlord charge for a late fee?

Late fees are usually set as a flat amount or a percentage of the rent, and many leases include a short grace period before the fee applies. What you can legally charge varies widely by jurisdiction, with some places capping the amount or requiring it to be reasonable relative to the rent.

A late fee should encourage on-time payment, not punish. Keep it within local limits, state it clearly in the lease, and apply it consistently. This calculator helps you compare a flat fee against a percentage so you can pick a fair, enforceable amount.

Try it with your own numbers →

Frequently asked questions

Late fees are commonly a flat amount or a percentage of the rent, often around 5% of monthly rent, though practice and legal limits vary. Many leases also include a grace period of a few days before the fee applies. Local law may cap the amount.
Often yes. Many jurisdictions require late fees to be reasonable, cap them at a set percentage of rent, or mandate a grace period. Charging more than the law allows can make the fee unenforceable, so confirm your local rules before setting one.
Both are common. A flat fee is simple and predictable; a percentage scales with the rent. The right choice depends on your leases and local limits. This calculator lets you compare the two so you can choose the approach that is fair and compliant.
A grace period is a short window after the due date during which rent can be paid without a late fee, often a few days. It is set in the lease and sometimes required by law. After the grace period ends, the late fee applies.