Hot Water Mixing Calculator

Estimate the hot and cold water portions needed to reach a target mixed temperature.

Estimated result

How this calculator works

Estimate the hot and cold water portions needed to reach a target mixed temperature.

Hot portion = total × (target − cold) ÷ (hot − cold)

Planning note

Results are estimates. Confirm local plumbing codes, product specifications and licensed-professional requirements before construction or safety-critical work.