Weighted Average Coupon (WAC) Calculator
Balance-weighted coupon of a loan pool or bond book — the WAC that drives MBS pass-through pricing.
Formula
MBS investors earn the net coupon — gross WAC minus servicing and guarantee fees. The WAC-vs-current-rate gap drives prepayment incentive: pools with WAC 150 bp above market refinance fastest, crushing premium pass-throughs.
Not financial advice — for informational and analytical use only. Verify all figures with a qualified professional before acting on them.
Disclaimer: This tool is for general informational and estimation purposes only and is not professional financial, tax, accounting or legal advice. All figures are estimates — verify with a qualified professional before making decisions. Read the full disclaimer.
Need weighted average coupon calculator results fast? Analysts, founders, traders and finance professionals use the Weighted Average Coupon Calculator to skip the spreadsheet and get a defensible answer in one step — free, private and instant.
About Weighted Average Coupon (WAC) Calculator
Balance-weighted coupon of a loan pool or bond book — the WAC that drives MBS pass-through pricing. MBS investors earn the net coupon — gross WAC minus servicing and guarantee fees. The WAC-vs-current-rate gap drives prepayment incentive: pools with WAC 150 bp above market refinance fastest, crushing premium pass-throughs. The governing relationship is WAC = Σ Bᵢ·cᵢ / Σ Bᵢ; net = WAC − fees. The Weighted Average Coupon Calculator computes entirely in your browser — free, private (your figures never leave your device) and instant, recalculating live as you change any input.
How to use Weighted Average Coupon (WAC) Calculator
- 1Enter Pool 1 — balance (currency), Pool 1 — rate (%), Pool 2 — balance (currency), Pool 2 — rate (%), Pool 3 — balance (0 = none) (currency), Pool 3 — rate (%) into the Weighted Average Coupon Calculator.
- 2The result is computed automatically using WAC = Σ Bᵢ·cᵢ / Σ Bᵢ; net = WAC − fees — there is no button to press.
- 3Change any input to model a different scenario, then copy or share the result.
Why use Weighted Average Coupon (WAC) Calculator?
- ✓Computes weighted average coupon calculator instantly with the correct formula — no spreadsheet needed
- ✓100% free and unlimited, with no sign-up, login or paywall
- ✓Runs entirely in your browser, so the figures you enter stay private
- ✓Shows the formula, a live worked example and references so you can defend the number
Frequently asked questions
What is the formula behind the Weighted Average Coupon Calculator?+
Weighted Average Coupon Calculator uses WAC = Σ Bᵢ·cᵢ / Σ Bᵢ; net = WAC − fees. MBS investors earn the net coupon — gross WAC minus servicing and guarantee fees. The tool substitutes your actual inputs into this relationship and shows the worked example step by step.
What inputs does the Weighted Average Coupon Calculator need?+
Enter Pool 1 — balance (currency), Pool 1 — rate (%), Pool 2 — balance (currency), Pool 2 — rate (%), Pool 3 — balance (0 = none) (currency), Pool 3 — rate (%) and the result updates immediately — there is no button to press. Change any value to model a different scenario in real time.
Is the Weighted Average Coupon Calculator free, and is my data private?+
Yes — it is completely free with no sign-up or usage limit, and it runs entirely in your browser, so the numbers you enter are never uploaded or stored on any server. It is for informational and analytical use, not financial advice.
What should I watch out for when using the Weighted Average Coupon Calculator?+
The WAC-vs-current-rate gap drives prepayment incentive: pools with WAC 150 bp above market refinance fastest, crushing premium pass-throughs.
What is the Weighted Average Coupon Calculator based on?+
The method follows authoritative sources: Fabozzi — mortgage-backed securities. The formula and references are shown on the page so you can verify and cite the result.
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