Prorated Rent Calculator
Calculate rent for a partial month when moving in mid-month or moving out before month-end. Supports banker's method (most common), days-in-month, and daily rate calculations.
Reviewed & updated for 2026 by Rakesh Choudhary, PhD · How we calculate
The three proration methods and which one favors whom
Banker's method (rent ÷ 30): The most common method in residential leases. It treats every month as if it has 30 days. For a $2,000 rent and 15 days occupancy, prorated = 2000/30 × 15 = $1,000. Pros: simple, consistent across all months. Cons: in months with 31 days, tenants pay slightly more per actual day; in February, slightly less.
Actual days in month (rent ÷ days-in-month): Divides rent by the actual number of days in that specific month. For $2,000 rent in July (31 days) with 15 days occupancy: 2000/31 × 15 = $967.74. Same scenario in February (28 days): 2000/28 × 15 = $1,071.43. Mathematically purer but produces month-to-month variance.
Annual rate (annual rent ÷ 365): Treats rent as a daily rate based on the full year. $2,000/month × 12 = $24,000 annual ÷ 365 = $65.75/day. For 15 days: $986.30. This method most accurately reflects "what the unit is worth per day" over the long run.
Which favors whom: Banker's method is roughly neutral. Actual-days-in-month favors landlords in February (higher per-day rate) and favors tenants in 31-day months (lower per-day rate). The 365-method usually produces the lowest prorated amount for tenants. If your state allows landlord choice and you're a tenant, ask for banker's method as a sensible default.
When proration is required vs optional
Proration is almost universally expected for move-in dates that fall mid-month. The landlord can't deny rental on the basis of move-in date but also can't require a full month for a partial month, that would be unjust enrichment.
Move-out is the trickier scenario. Most leases require a "full final month" regardless of actual move-out date because the landlord usually can't re-rent for half a month. If your lease ends June 30 and you move out June 15, you still owe June rent in full unless your lease explicitly allows proration. The leverage point: negotiate an early termination addendum at lease signing if you anticipate a possible mid-month moveout.
State laws vary on tenant rights. California, New York, Massachusetts, and most tenant-friendly states require fair proration for move-in. Texas, Florida, and many southern/western states leave it more to lease language. Always read the proration clause carefully; standard residential lease forms (like the California Association of Realtors lease) include proration formulas you can verify against the landlord's invoice.
Common scenarios and what they cost
Scenario 1, Mid-month move-in: $1,800/month rent, moving in March 18, lease starts that date. Banker's method: $1,800/30 × 14 = $840 for first month. Plus $1,800 for full month of April. First month payment due at move-in: $840 first-month prorated rent + $1,800 second month + $1,800 security deposit (typical) = $4,440 cash needed at signing.
Scenario 2, Lease starts on the 1st but moving in late: Lease begins April 1 at $1,800/month, but you can't actually move in until April 10. You still owe full April rent (the unit was available; you chose not to use it). However, if the landlord agreed to a later move-in date in writing, the lease would specify prorating from move-in. Always get this in writing.
Scenario 3, Last month is partial: Lease ends June 15. Most leases require full June rent. Negotiation opportunity: offer to leave the unit ready for showings starting June 1 in exchange for proration. Landlord gets a head start on re-renting; you save half a month's rent. Win-win when both parties are reasonable.
FAQs
What is prorated rent?
Prorated rent is rent paid for a partial month, when you move in mid-month or move out before month-end. Instead of paying full month, you pay for only the days you occupy the unit.
How is prorated rent calculated?
Three common methods. (1) Banker's method: monthly rent / 30 × days occupied. (2) Days-in-month method: monthly rent / actual days × days occupied. (3) Daily rate method: annual rent / 365 × days. Banker's method is most common and tenant-friendly.
Example: $2,000/month, moving in on the 15th, what's the prorated rent?
Days occupied: 15-30 = 16 days (counting both first and last). Banker's method: $2,000 / 30 × 16 = $1,066.67. Days-in-month method (30-day month): same result. Days-in-month (31-day month): $2,000 / 31 × 16 = $1,032.26. Most leases use banker's method.
Is prorated rent required by law?
Generally yes if the landlord moves you in or out mid-month. Some leases allow the landlord to require a full month payment for partial occupancy (which is unfair but sometimes legal depending on state). Always confirm proration in your lease, California, New York, and most tenant-friendly states require fair proration.
What if I move out mid-month?
Most leases require full month's rent if you move out mid-month UNLESS the lease ends mid-month. The landlord's argument: they can't easily re-rent a unit for half a month. Negotiate for mid-month moveout if you have leverage, but expect to pay full month if your move date isn't lease-aligned.
Does proration include utilities?
Usually yes for utilities the landlord pays as part of rent (e.g., water, trash, common-area electric). Tenant-paid utilities (your separate electric, internet) are NOT prorated, you pay your actual usage for the partial month from those providers directly.