Formula & example
QBTU/h≈500·GPM·ΔT°F; tons=Q/12000.
At 10°F ΔT, 24 tons needs about 57.6 GPM of water.
HVAC engineering calculator · Updated Sep 17, 2026
Chilled Water Flow Calculator — GPM, kW, Tons & ΔT
Calculate chilled-water flow from cooling load and temperature difference, or show the carried load for an entered GPM.
Inputs
Result
Cooling load 288,000 BTU/h
Cooling load 84.404468 kW
Cooling capacity 24 ton
Water flow 57.6 GPM
Water flow 3.6339955 L/s
Assumptions & limits
- The 500 factor approximates water near common HVAC temperatures.
- Glycol mixtures require corrected density and specific heat.
Frequently asked questions
What does this Chilled Water Flow Calculator calculate?
Calculate chilled-water flow from cooling load and temperature difference, or show the carried load for an entered GPM.
Can I use SI and US customary units?
Yes. The calculator exposes the unit basis in the inputs and reports useful cross-unit outputs where the engineering workflow benefits from them.
Is this a replacement for HVAC design software?
No. It is a transparent deterministic engineering calculator for sizing, diagnostics and cross-checks. Final equipment, duct and refrigeration decisions should use measured conditions, manufacturer data and applicable codes or standards.