Multiply the payment used for your reserve calculation by the required number of months. This calculator turns those inputs into a dollar target, then compares it with the funds you expect to have left after closing. It does not decide which reserve rule or assets your lender will accept.
What you enter
Enter the monthly payment basis and the required reserve months from your proposed program review. Then enter eligible assets before closing, the cash needed for closing and any other spending already committed from those funds.
If your assets include a retirement or brokerage account, enter only the value confirmed as eligible for this particular review. The calculator does not apply a guessed discount or assume that the full balance counts. Keep the source statement date beside the amount.
Use a separate field for your operating cash goal. Loan reserves may be measured from the housing payment, while your own budget may also need to cover utilities, repairs or furnishing. Clearing the entered loan target does not mean that the business has enough working cash.
Example
Assume a $3,200 monthly payment basis and a requirement of six months for this example only. The target is $19,200. Assume $125,000 of eligible funds before closing, $100,000 needed at closing and $8,000 committed to other immediate spending.
That leaves $17,000 available against the $19,200 target, a shortfall of $2,200. These are made up figures. Six months is an example input and is not presented as a lender requirement.
If you reduce a purchase cost, verify the new loan payment before rerunning the calculation. A smaller down payment might preserve cash while also changing the payment used to calculate reserves. Both sides of the comparison need updating.
How many months of reserves do I need?
The required months need to be confirmed for the actual program, loan amount, property use and transaction. There is no sourced typical DSCR reserve range established here.
Enter the confirmed requirement rather than selecting a number that makes the result look comfortable. See DSCR Loan Requirements in Florida: Credit, Down Payment, Ratio, Reserves and Documents for the broader review.
What counts as reserves?
For this calculator, it is the eligible asset value left after closing and the commitments you have entered. Whether cash, securities, retirement funds or business assets qualify must be checked against the proposed program.
Do not count money already used for the down payment again as money left. Do not treat an unverified account balance as an approved reserve asset.
How do reserves change with several properties?
That requires the actual rule for the subject property and any additional property requirement. The calculator can add separate confirmed targets, but it should not assume that every property uses the same months or payment basis.
It should also show one shared pool of assets. Counting the same dollars once for each property can make a portfolio look better funded than it is.
What if my cash is thin after closing?
Check the shortfall against both the confirmed reserve target and your own operating budget. Then compare a different purchase price, cash contribution or financing structure using updated figures.
For a vacation rental, keep the launch spending visible. Cash earmarked for furniture is already doing another job.
This calculator gives an estimate only. It is not a loan offer or approval.
Sources
- CFPB Mortgage payment components. What goes into my total monthly mortgage payment; reviewed August 28, 2023. Checked October 16, 2026.
- Fannie Mae Mortgage Calculator. Disclaimer; How to use this calculator. Checked October 16, 2026.