Prorate Rent Calculator

What Is Prorate Rent Calculator?

The Prorate Rent Calculator determines the exact portion of a monthly rent that a tenant owes (or should be credited) when occupancy starts or ends partway through a billing period. By converting a monthly figure into a precise daily rate, then multiplying by the number of billable days, the calculator removes guesswork and disagreement. It supports common rules—actual days in the month, a 30-day convention, or a 365/366-day annual basis—and clearly shows the steps, so both landlords and tenants can audit results. In addition to base rent, it can prorate recurring add-ons (parking, pets, storage) and apply taxes where relevant. Because each assumption is explicit (which days count, which basis is used, rounding), the Prorate Rent Calculator creates transparent, repeatable outcomes for leases, renewals, and early terminations.

About the Prorate Rent Calculator

This calculator accepts move-in and move-out dates, monthly rent, and your proration rule. It can include recurring charges and recurring credits, optional tax, and a rounding policy (to cents or to the nearest dollar). Results itemize the daily rate, billable days, base prorated amount, add-ons/credits prorated at the same ratio, tax, and final balance due or refund. For mid-month rent changes, it splits the month into segments and weights each segment by its own daily rate. For multi-month spans, it sums monthly prorations so months with different lengths remain accurate. Clear formulas allow you to reuse the math in invoices, ledgers, or tenant communications.

How to Use this Prorate Rent Calculator

1) Enter monthly rent and select a proration basis (Actual-days, 30-day, or Annual 365/366). 2) Provide the start and end dates to count billable days; choose whether the end date is inclusive or exclusive (typical practice: include the start day, exclude the end day). 3) Add recurring add-ons/credits and tax rate if applicable. 4) Choose rounding. 5) Submit to see daily rate, billable days, prorated base, add-ons/credits, tax, and net due or refund. 6) For rent changes mid-month, add a second monthly rate with the effective date; the calculator will weight both segments automatically.

Examples Using the Prorate Rent Calculator

Example A (Actual-days, 30-day month): Rent $1,500, move-in on the 10th; billable days = 21 → daily = 1,500/30 = $50; prorated = $1,050.

Example B (31-day month comparison): Rent $1,800, move-in on the 20th; billable days = 12 → Actual-days daily = 1,800/31 ≈ $58.06; prorated ≈ $696.77. 30-day rule daily = $60; prorated = $720.

Example C (Move-out credit): Paid full $2,000 for a 28-day month, vacate after 10 days (exclusive end). Billable = 10 → owed = (2,000/28)×10 ≈ $714.29; refund ≈ $1,285.71.

Example D (Mid-month increase): $1,400 until the 15th, then $1,500. In a 30-day month, days at old rate = 14, new rate = 16 → prorated = (1,400/30)×14 + (1,500/30)×16.

Core Formulas (rendered responsively)

If you include both start and end, use \(n = d_{\text{end}} - d_{\text{start}} + 1\).

\(R_m\) is monthly rent; \(D_m\) is days in the month (28–31).

Some leases standardize to a 30-day month for simplicity.

When your policy derives per-diem from annual rent.

Multiply the chosen daily rate by the counted days.

Weight each period by its own rate and day count.

Recurring charges or credits scale proportionally to base rent.

Apply tax rate \(\tau\) if required in your jurisdiction.

Positive means amount due; negative indicates a refund.

FAQs

Which proration method should I use?

Follow the lease or local policy. If unspecified, Actual-days is common; some landlords use a 30-day convention for simplicity.

Do I count the move-in day?

Typically yes; the end day is often excluded. Your lease should define this—stay consistent with that rule.

How do leap years affect calculations?

Annual-basis per-diem uses 366 for leap years. Actual-days and 30-day methods are unaffected beyond February’s length.

Are utilities and parking prorated too?

Recurring items usually are; one-time fees (application, key) typically aren’t. Check your lease language.

What if the rent changes mid-month?

Split the month into segments and prorate each at its own daily rate, then sum the results.

Can I prorate across two months?

Yes. Compute each month separately using its length and rate, then add both prorations.

How should I round the result?

Most ledgers round to cents. Some offices round to the nearest dollar; choose a consistent policy.

Is deposit money prorated?

Security deposits are generally not prorated; they’re separate from rent and governed by state or lease rules.

What if I prepaid the full month but leave early?

Calculate the owed portion for the occupied days and refund the difference according to the lease and payment status.

Does weekend or holiday move-in matter?

No. Proration is day-based, not business-day based, unless your lease specifies otherwise.

Why is my total different from the landlord’s?

Likely a different day-count rule, rounding, or handling of add-ons. Compare formulas line by line to reconcile.