Principles
- Use straightforward formulas that can be checked by hand.
- Show assumptions directly on the page instead of burying them.
- Separate calculation help from legal, tax, or market advice.
Methodology
Transparent formulas first.
These calculators are built to show the math clearly, keep assumptions visible, and make the result easy to verify.
How results are rounded
Dollar amounts are rounded to the nearest cent. Percent outputs are shown as percentages, and totals are calculated from the rounded line items shown on the page.
Calculator methods
- Prorated rent: Monthly rent is divided by either the actual days in the month or a fixed 30-day method, then multiplied by occupied days.
- Move-in cost: First month rent, deposits, prorated rent, and fees are added into one total due figure.
- Rent increase: The tool works from either a target rent or a percentage increase, then shows both the dollar and percent change.
- Late fee: The tool applies a flat fee, a percent fee, or both, then adds the fee total to unpaid rent.
What the tools do not do
- They do not interpret lease language for you.
- They do not verify whether a fee, increase, or proration method is legal in your area.
- They do not replace your ledger, notice process, or compliance review.
Important note
These tools provide calculation support only. Lease language, local law, notice rules, fee caps, and compliance requirements vary by location and should be verified independently.