T-Bill Discount Yield Calculator
Compute the Bank Discount Yield (BDY) of a T-bill.
Your T-bill numbers never leave your browser — all math runs locally.Try: Face value=1000, Purchase price=980, Days to maturity=182 → $1,000, $980, $20, 0.0396%, 0.0409%, 0.0409%
How to use
BDY = (Face − Price) ÷ Face × (360 ÷ days). It is the yield quoted at auction but understates your true return.
FAQ
Why does BDY look low?
It divides by face value, not your cost, and assumes a 360-day year — both push the number down.
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