# What equation will convert implied yield volatility to implied price volatility?

I am trying to figure out how to turn implied yield volatility of a short-term interest rate into implied price volatility. Is there an equation to do this?

I have come across the equation for a bond: (price_vol = yield_vol*modified_duration*forward_yield) But, I do not believe this is correct for a STIR option.

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This seems to work very well for at-the-money options: yield_vol*(100-futures_price) –  Stu May 6 at 15:45