What the calculator estimates
On an interest-only loan the balance does not fall, so interest is simply principal times the annual rate times the fraction of a year the loan is outstanding. $10,000,000 at a 10% annual rate for 18 months is $1,500,000 of interest, or $83,333 a month. The rate in the example is an illustration, not a term.
The monthly figure is the carry a property has to cover from operations, an interest reserve, or the sponsor's own funds until the exit repays the loan.
What it leaves out
Bridge loans also carry origination fees, exit fees, extension fees, and legal and third-party costs, none of which appear here. Floating-rate loans change the payment as the index moves, and some loans accrue part of the interest rather than paying it currently.
A longer plan costs more than the arithmetic suggests. Beyond the extra months of interest, extensions usually carry a fee and sometimes a rate step-up, and the market a sponsor refinances into may have moved.
Using the result in a budget
Sponsors typically place expected carry into an interest reserve funded at closing or drawn over time. Comparing the total interest for a 12-, 18-, and 24-month plan shows how much a schedule slip costs and how much contingency the budget needs.
The result is an arithmetic output from the numbers you enter. It is not a quote, a term, or an underwriting decision, and H Equities does not see or store what you type.