A forward rate is the interest rate implied by the current yield curve for a future period. It is derived from the no-arbitrage condition: investing for two years at the 2-year spot rate must produce the same return as investing for one year at the 1-year spot rate and then reinvesting for one year at the 1-year rate, one year forward.
Mathematically, the 1-year rate, 1-year forward (denoted 1y1y) satisfies:
(1 + r_2)^2 = (1 + r_1)(1 + f_{1,1})
where r_1 and r_2 are the 1-year and 2-year spot rates, and f_{1,1} is the forward rate.
Forward rates serve multiple purposes:
The forwards tool on this site computes and visualizes the implied forward curve for any horizon, allowing users to see what the current par curve implies about future rate levels. A steep forward curve suggests the market prices higher future rates (or positive term premium), while a declining forward curve suggests expectations of lower rates.