# How do you calculate or estimate the future gross basis of a treasury future?

Gross Basis for treasury futures = clean price - future price* conversion factor

Is there a way to estimate the gross basis, say 10 days from now, given that you know what the forward bond price is?

Conversion factor is constant as well.

Gross basis today is as your formula: $$GB_{today} = P_{today} - F*C_f$$ Forward gross basis depends on the future price of the bond: $$GB_{forward} = P_{forward} - F*C_f$$ The important part being the futures price is not expected to change. You stated you know what forward price is but for clarity it is: $$P_{forward} = P_{today} * (1 + dayfrac * reporate)$$