⏱️ Reaction Rate Calculator

What reaction rate measures

The rate of a chemical reaction describes how quickly reactants are consumed or products form. The average rate over a time interval is a straightforward way to quantify reaction speed from two concentration measurements.

The formula used

Average rate = |Δ[species]| ÷ Δt, where Δ[species] is the final concentration minus the initial concentration, and Δt is the elapsed time. Because different species in a balanced equation change at rates proportional to their stoichiometric coefficients, the rate is also divided by the coefficient of the species you measured so it reflects the overall reaction rate rather than that species alone.

• Use a positive time interval; the calculator reports rate as a positive (magnitude) value.
• Leave the stoichiometric coefficient at 1 if you simply want the rate of change of the measured species itself.

This calculator gives an average rate over the chosen interval, not the instantaneous rate at a single moment; for reactions with strongly curved concentration-time plots, use a shorter interval for a closer approximation. Intended for general chemistry education purposes.