The Renter's Ledger
Model old-home and new-home rent separately with actual calendar-day proration, then add optional transition expenses.
Enter the dates when responsibility for the new home starts and the old home ends. This worksheet uses actual calendar days and does not decide how either lease bills prorated rent.
Inclusive dates
The modeled overlap begins on the new-home responsibility start date and ends on the old-home responsibility end date. If both dates are the same, the result contains one overlapping calendar day. Adjacent leases and gaps contain zero overlapping days.
Actual calendar months
For each home, monthly rent is multiplied by overlap days in that calendar month and divided by the actual 28, 29, 30, or 31 days in that month. Each home-month segment is rounded once to the nearest cent, then the rounded segments are summed.
Narrow planning boundary
Enabled moving, lodging, storage, utility setup, and other one-time transition expenses are added to combined overlap rent. The timing of those expenses may differ, so the final number is a modeled total across the entered period.
Formula
Modeled transition cash = separately prorated old-home overlap rent + separately prorated new-home overlap rent + entered transition expenses.
Deliberate exclusions
For August 20 through August 31, $2,400 old rent models $929.03 and $2,700 new rent models $1,045.16, for $1,974.19 combined overlap rent.
For January 20 through February 10 in 2026, each home's rent is split into a 12/31 January segment and a 10/28 February segment before the rounded segments are summed.
If the new responsibility starts on the same date the old responsibility ends, both inclusive boundaries create one overlapping calendar day.
If old responsibility ends one day before new responsibility begins, overlapping rent is zero.
A gap has zero overlapping rent, but entered temporary lodging can remain in modeled transition cash.
In a 31-day month, actual calendar-day proration uses 31 as the divisor rather than a fixed 30-day assumption.
Each home's monthly rent is prorated independently for the inclusive overlap days in each affected calendar month, using the actual days in that month. Rounded home-month segments are then summed.
Yes. The new responsibility start date and old responsibility end date are both inclusive. If they are the same date, the calculator models one overlapping calendar day.
Adjacent leases and gaps produce zero overlapping rent. Optional nonrefundable transition expenses can still be included in modeled transition cash.
A lease may use a fixed 30-day divisor, another written proration rule, or different responsibility dates. Verify the billing language in both leases.
The optional section accepts moving, temporary lodging, storage, utility setup or transfer charges, and other one-time nonrefundable transition costs. Refundable deposits are excluded.
Last reviewed August 11, 2026 - This calculator provides an informational estimate and is not legal, financial, tax, or housing advice.
