How to estimate the current balance of an SBA loan
The SBA FOIA file tells you what a borrower was approved for — not what they owe today. But it gives you everything needed to estimate it: amount, term, rate, and dates. Standard amortization math turns those four fields into a credible balance estimate, a payment estimate, and the dollars-per-month number that opens a refinance conversation.
What you need from the FOIA file
Four fields per loan:
grossapproval— the original principal, Pterminmonths— the term, ninitialinterestrate— the annual rate at origination (monthly rate r = annual ÷ 12)firstdisbursementdate(orapprovaldateif blank) — to count k, the full months elapsed
Prefer the disbursement date over the approval date when both exist — the clock starts when money moves. And before running any math, check revolverstatus: revolving lines of credit don't amortize, so this method doesn't apply to them.
The two formulas
1. Scheduled monthly payment
This is the standard fixed-payment amortization formula: the payment that retires principal P over n months at monthly rate r.
2. Remaining balance after k payments
Same ingredients, one more input: k, the number of payments already made. This is the scheduled balance — what's left if the borrower has paid exactly on schedule.
In Excel or Google Sheets, both are one-liners:
A worked example
A contractor took a $500,000 SBA 7(a) loan, 10-year term (120 months), originated three years ago at an initial rate of 10.25%, variable. The FOIA row gives you everything:
| Step | Value |
|---|---|
Original principal (grossapproval) | $500,000 |
| Monthly rate (10.25% ÷ 12) | 0.8542% |
| Scheduled monthly payment (120 mo) | ≈ $6,677 |
| Payments made (36 of 120) | 30% of term |
| Estimated remaining balance | ≈ $399,000 |
Note what the math just told you: after 30% of the term, roughly 80% of the principal is still outstanding. Early amortization is mostly interest. That asymmetry is exactly why seasoned loans are refinance targets — there's still a large balance left to reprice.
From balance to the pitch
Suppose you can offer 8.50% on the estimated $399,000. Two ways to structure it, two different conversations:
| Structure | New payment | Monthly change |
|---|---|---|
| Refi over the remaining 84 months (same payoff date) | ≈ $6,320 | −$357 |
| Refi over a fresh 120 months | ≈ $4,948 | −$1,729 |
The like-term row is the honest measure of pure rate savings. The fresh-term row is the bigger cash-flow headline — but it adds three years of payments, so present it as a cash-flow choice, not free money. A credible brief carries both numbers; borrowers (and their CPAs) notice when you only show the flattering one.
The variable-rate wrinkle
Most 7(a) loans float over Prime, and the FOIA file only shows the initial rate. Two practical consequences:
- The balance estimate holds up better than you'd think. Variable 7(a) loans are typically re-amortized over the remaining term at each rate reset, which keeps the loan near its original maturity schedule. So the elapsed-time balance estimate stays in the ballpark even after big rate moves — the rate path mostly changed their payment, not their payoff date.
- The payment estimate should use today's rate, not the initial one. What the borrower pays now reflects current Prime plus their spread. Reconstruct the spread from the initial rate and the Prime rate on the origination date, add it to today's Prime, and re-run the payment formula on the estimated balance. That number — their payment now versus your offer — is the pitch.
Know what the estimate can't see
- Prepayments. Extra principal payments are invisible in public data. (SBA 7(a) loans with terms of 15+ years generally carry a prepayment charge in their first three years; shorter terms don't — so prepayment on a 10-year working-capital loan is common.)
- Deferments and modifications shift the schedule — COVID-era deferments especially.
- Revolvers don't amortize. Filter them out with
revolverstatus. - It's a conversation-sizer, not a payoff quote. You're establishing whether the balance is $200k or $400k and whether the savings story is real. The exact payoff figure comes from the borrower, on the call you just earned.
Doing this at scale
For one loan, this is a spreadsheet row. For a prospect list, it's the workflow in our guide to finding SBA 7(a) prospects: filter the FOIA universe, estimate balances, screen for rate spread, then research the survivors. Curter runs the whole chain automatically — every brief Curt writes includes a lending projection with the estimated balance, current-versus-offer payment delta, and lifetime interest delta already computed, each input cited to its source.
Common questions
Does the SBA FOIA dataset show the current loan balance?
No — it shows the gross approval amount, term, initial rate, and dates. The remaining balance has to be estimated, which is what the amortization math on this page does.
How accurate is the estimate?
Good enough for prospecting, not for closing. It assumes scheduled payments — prepayments, deferments, and modifications aren't visible in public data. You're sizing the conversation, not quoting a payoff.
What rate should I use for a variable-rate loan?
The initial rate is fine for the balance estimate, because variable 7(a) loans typically re-amortize at each reset and stay near their original maturity schedule. For the borrower's current payment, reconstruct their spread (initial rate minus Prime at origination) and apply it to today's Prime.
Why is so much principal left early in the loan?
Early payments are mostly interest. On a 10-year loan around 10%, roughly 80% of principal remains after 3 years. That front-loading is exactly why seasoned loans are worth refinancing — most of the balance is still there to reprice.
The projection, already run
Every Curter brief includes this math — estimated balance, payment delta, lifetime interest delta — computed per prospect and cited. Describe the borrower you want; walk in with the numbers.
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