Rex says
Money math without the spreadsheet headache. Plug in your numbers and I'll show you exactly where the dollars land.
Try a scenario
Click to load — tweak from there.Inputs
Result
Projected annual late fee revenue
$2,880
Monthly late fee revenue
$240
Typical fee per late payment
$80.00
State cap amount (if applicable)
$75.00
Amount your fee exceeds the cap
$5.00
Psst — share this and help Rex grow
One click, a permanent link with your numbers baked in.
How to use this
- 1Enter number of units.
- 2Enter average monthly rent ($).
- 3Enter share of tenants paying late each month (%).
- 4Enter flat late fee ($).
- 5Enter additional daily fee ($/day).
- 6Enter average days late when it happens (days).
- 7Enter state cap on late fee (% of rent, if any) (%).
- 8Read your projected annual late fee revenue on the right — it updates as you type.
- 9Hit Share to keep the scenario or send it to someone.
About this calculator
Late fees exist to change behavior, not to become a profit center, but on a portfolio of any size they do add up and many states cap how much you can charge. This calculator projects annual late fee revenue from your current policy — a flat fee, a daily fee, or a percentage of rent — based on how often tenants actually pay late, and flags whether your fee looks aggressive against common state caps (many states limit late fees to 5% of rent or require a grace period before any fee applies). Getting the fee wrong in either direction costs you: too low and it doesn't deter late payment, too high and you risk an unenforceable clause or a habitability/fee dispute.
Worked example
Using the values the calculator loads with:
Inputs
- Number of units: 20
- Average monthly rent: 1500 $
- Share of tenants paying late each month: 15 %
- Flat late fee: 50 $
- Additional daily fee: 5 $/day
- Average days late when it happens: 6 days
- State cap on late fee (% of rent, if any): 5 %
Results
- Projected annual late fee revenue: $2,880
- Monthly late fee revenue: $240
- Typical fee per late payment: $80.00
- State cap amount (if applicable): $75.00
- Amount your fee exceeds the cap: $5.00
What each field means
Inputs
- Number of units
- The number of units used in the calculation. Starts at 20 so you have a working example on load.
- Average monthly rent ($)
- The average monthly rent used in the calculation, measured in $. Starts at 1500 $ so you have a working example on load.
- Share of tenants paying late each month (%)
- The share of tenants paying late each month used in the calculation, measured in %. Starts at 15 % so you have a working example on load. Accepted range: 0–100 %.
- Flat late fee ($)
- The flat late fee used in the calculation, measured in $. Starts at 50 $ so you have a working example on load.
- Additional daily fee ($/day)
- The additional daily fee used in the calculation, measured in $/day. Starts at 5 $/day so you have a working example on load.
- Average days late when it happens (days)
- The average days late when it happens used in the calculation, measured in days. Starts at 6 days so you have a working example on load. Accepted range: 0–30 days.
- State cap on late fee (% of rent, if any) (%)
- The state cap on late fee (% of rent, if any) used in the calculation, measured in %. Starts at 5 % so you have a working example on load. Accepted range: 0–25 %.
Results
- Projected annual late fee revenue
- Returned as a money amount in US dollars and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Monthly late fee revenue
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Typical fee per late payment
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- State cap amount (if applicable)
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Amount your fee exceeds the cap
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
What states cap late fees?
Many states either cap the fee as a percentage of rent (often 5%) or require it to be a 'reasonable' pre-estimate of actual damages, with no fixed number. California, for instance, doesn't set a hard percentage but courts have found fees exceeding roughly 5-10% of rent hard to defend as reasonable rather than punitive.
Should I use a flat fee, daily fee, or percentage?
A modest flat fee plus a small daily fee after a grace period tends to be both compliant and effective — it punishes chronic lateness more than a one-time slip. Pure percentage-of-rent fees are simple to calculate but can look punitive on higher-rent units, inviting more legal scrutiny.
Does a grace period reduce revenue much?
Yes, usually by 30-50%, because a meaningful share of 'late' payments arrive within the first 3-5 days. Most leases include a grace period anyway since courts and many states expect one before any fee is enforceable.
Is high late fee revenue a red flag?
It usually signals either weak tenant screening or cash-flow-strapped tenants who can't consistently make rent on time, not a healthy revenue stream. Chasing late fee income instead of fixing the underlying screening or affordability mismatch tends to correlate with higher turnover and collection losses.
Accuracy and limitations
- Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
- Rates are treated as fixed for the whole period — variable-rate products will drift from this projection.
- This is educational maths, not financial advice. Check anything contractual with the lender or your accountant.
Related tools
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Late Fee Policy Revenue Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/late-fee-revenue-projection
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/late-fee-revenue-projection" target="_blank" rel="noopener">Late Fee Policy Revenue Calculator — RevenueLab</a> (2026).</p>
Source: [Late Fee Policy Revenue Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/late-fee-revenue-projection) (2026).