Watts to BTU Calculator

Convert watts to BTU/h (or reverse BTU/h to watts & kW) instantly—bidirectional thermal power conversion for heaters, AC capacity labels, and HVAC planning.

Calculator

Quick: watts → BTU/h. Advanced: reverse direction, W/kW, and BTU/min or BTU/s rates.

Conversion direction

BTU rate unit Primary result unit for Power → BTU, or input unit for BTU → Power. 1 RT = 12,000 BTU/h. Results always list companions including RT.

Power

Example: 1000 W heater or 5 kW electric load. Use kW for industrial ratings.

About this calculator

This watts to BTU calculator converts thermal power between W, kW, BTU rates (BTU/h, BTU/min, BTU/s), and refrigeration tons (RT) where 1 RT = 12,000 BTU/h. It is not an energy converter (BTU ↔ kWh) and not a room-load sizer—use the HVAC capacity calculator for tons from floor area. Browse the power calculator hub.

Calculation Results

≈ 3,412 BTU/h (0.28 ton ref.)

1000 W · 1.000 kW · 3,412 BTU/h

Formula: BTU/h = W × 3.412141633

BTU/h is thermal capacity rate, not electrical input. Actual AC watts depend on EER/COP/SEER. 1 refrigeration ton ≈ 12,000 BTU/h (reference only).

Continue Your Calculation

Have thermal capacity in BTU/h or kW? Screen tons from floor area with HVAC capacity (not a substitute for Manual J).

HVAC capacity →

Watts to BTU/h quick reference

Uses IT factor 3.412141633. Click a row to load the calculator.

Input	Context	Result
	Space heater class	≈ 3,412 BTU/h
	Portable heater	≈ 5,118 BTU/h
	Electric heat / plant	≈ 17,061 BTU/h
	≈ 1 ton AC	≈ 3,517 W
	Refrigeration ton	12,000 BTU/h ≈ 3,517 W
	≈ 2 ton AC	24,000 BTU/h ≈ 7,034 W
	≈ 2 ton AC	≈ 7,034 W

Watts to BTU formula (incl. refrigeration ton)

Watts → BTU/h: BTU/h = W × 3.412141633

kW → BTU/h: BTU/h = kW × 3412.141633

BTU/h → watts: W = BTU/h ÷ 3.412141633

Rate companions: BTU/min = BTU/h ÷ 60 · BTU/s = BTU/h ÷ 3600 · RT = BTU/h ÷ 12,000

BTU/h, BTU/min, BTU/s — thermal power rates (capacity), not energy BTU
RT (refrigeration ton) — 1 RT = 12,000 BTU/h ≈ 3.517 kW thermal
W / kW — SI power (here used as thermal-equivalent power)

Example: 1000 × 3.412141633 ≈ 3412.14 BTU/h ≈ 0.284 RT. 1 RT → 12,000 BTU/h ≈ 3,517 W.

Need room tons from area? HVAC capacity calculator. Need energy BTU ↔ kWh? BTU to kWh. Need line current from watts? Watts to Amps.

When to use which tool

Goal	Tool
Convert W/kW ↔ BTU/h / RT (power)	This page
Estimate tons from floor area	HVAC Capacity
Convert watts ↔ amps	Watts to Amps
Convert amps ↔ kW	Amps to kW

Frequently Asked Questions

How do I convert watts to BTU/h?

Multiply watts by 3.412141633. Example: 1000 W ≈ 3412.14 BTU/h. For kW, multiply by 3412.141633.

How do I convert BTU/min or BTU/s?

BTU/min = BTU/h ÷ 60; BTU/s = BTU/h ÷ 3600. Example: 1000 W ≈ 3412 BTU/h ≈ 56.87 BTU/min ≈ 0.948 BTU/s. Choose the unit in the BTU rate selector.

How do I convert BTU to refrigeration tons (RT)?

1 RT = 12,000 BTU/h. So RT = BTU/h ÷ 12,000. Example: 24,000 BTU/h = 2 RT. Use the RT unit or the 1 RT / 2 RT presets. Room tons from floor area still belong on HVAC capacity.

How do I convert RT to watts?

Convert RT → BTU/h first (×12,000), then ÷ 3.412141633. Example: 1 RT → 12,000 BTU/h ≈ 3,517 W (≈ 3.517 kW thermal).

How do I convert BTU/h to watts?

Divide BTU/h by 3.412141633. Example: 12,000 BTU/h ≈ 3516.85 W (≈ 3.517 kW).

Is BTU/h the same as electrical watts on an AC nameplate?

No. BTU/h is cooling/heating capacity. Electrical input depends on EER/COP/SEER. This calculator converts thermal power units only.

What is 5 kW in BTU/h?

5 × 3412.141633 ≈ 17,061 BTU/h. Use the 5 kW preset above.

Is this the same as BTU to kWh?

No. This page is power (BTU/h, /min, /s). Energy BTU ↔ kWh is a different conversion—use BTU to kWh.