BTU/s to Watts
Convert BTU per second to watts at the fixed ratio 1 BTU/s = 1,055.05585 W.
Interactive
Scale explorer for BTU/s to W
Drag the slider or click a tier to see where your BTU/s value lands on the equipment scale — with live W output.
Visual scale
BTU/s vs other BTU rate units
Same BTU rate, four different time bases. Click to compare.
Fundamentals
What is BTU/s to W?
BTU/s to Watts converts British Thermal Units per second to watts by multiplying the BTU/s value by 1,055.05585. One BTU equals 1,055.05585 joules (international BTU definition), and one watt equals one joule per second, so 1 BTU/s converts directly to 1,055.05585 W. The formula is P(W) = P(BTU/s) × 1,055.05585. BTU per second is less common than BTU/hr in HVAC labels but appears in physics, engineering coursework, and short-duration heat-flux problems where the per-second basis matches the data.
A BTU per second is a rate of thermal energy transfer expressed on a one-second basis. It is 3,600× larger than the more common BTU/hr (since one hour has 3,600 seconds), so 1 BTU/s = 3,600 BTU/hr.
Watts measure power in SI as one joule per second. The two units share the same time basis (per second), which makes the BTU/s ↔ W conversion the cleanest of the BTU-family conversions — only the energy unit changes.
BTU/s appears in heat-transfer textbooks, transient thermal analysis, and combustion calorimetry. It is rare on consumer HVAC labels, which almost universally use BTU/hr.
Formula
BTU/s to W formula
Convert 1 BTU/s — the rate at which the heat-equivalent of one BTU is delivered every second — to watts. The result, 1,055.06 W, equals about 1 kW.
How to convert BTU/s to W
Three steps complete the conversion:
Pull it from the textbook problem, calorimetry data set, or thermal analysis output.
This is the international BTU-to-joule conversion factor — exact to five decimal places.
Watts integrate directly into SI heat-transfer and power-balance equations.
Applications
When to convert BTU/s to W
Real-world scenarios where this conversion shows up in engineering, HVAC, and equipment specification work.
Convert textbook BTU/s problem data to watts for SI-based fluid-dynamics and conduction equations.
Reaction calorimeters often log thermal output per second — translate to watts for SI publications.
Finite-element solvers expect heat-flux inputs in watts; convert from BTU/s-rated source data.
Match per-second BTU release rates against electrical load equivalents in watts.
Compare instantaneous BTU/s gain on a collector to a watt-rated electrical input.
Guidance
Tips and common pitfalls
Confusing the two basis units gives an error of three orders of magnitude. Always confirm whether data is per-second or per-hour.
International BTU = 1,055.05585 J. Thermochemical BTU = 1,054.35 J. The difference is under 0.1%, but precise lab work should match definition to source.
Engineers usually convert W to BTU/hr (factor 3.412) rather than BTU/s. BTU/s is mostly a research-and-textbook unit.
Reference
BTU/s to W conversion table
| BTU per second (BTU/s) | Watts (W) |
|---|---|
| 0.001 BTU/s | 1.0551 W |
| 0.01 BTU/s | 10.5506 W |
| 0.1 BTU/s | 105.51 W |
| 0.5 BTU/s | 527.53 W |
| 1 BTU/s | 1,055.06 W |
| 2 BTU/s | 2,110.11 W |
| 5 BTU/s | 5,275.28 W |
| 10 BTU/s | 10,550.56 W |
| 25 BTU/s | 26,376.4 W |
| 50 BTU/s | 52,752.79 W |
| 100 BTU/s | 105,505.59 W |
| 250 BTU/s | 263,763.96 W |
| 500 BTU/s | 527,527.93 W |
| 1,000 BTU/s | 1,055,055.85 W |
In practice
Industry context and practical notes
Calorimeters and bench-scale thermal experiments often log on a per-second basis because the underlying measurement — a thermistor or thermocouple — samples in milliseconds. Reaction calorimetry for explosive or runaway reactions especially favors fast time-resolution; expressing heat release per second is more natural than per hour for events that finish in minutes. Older U.S. physics textbooks formalized this convention, and it persists in research papers and graduate-course problem sets. SI-based labs use W, but the BTU/s tradition remains in pockets of combustion research and U.S. military thermal testing.
A combustion bench experiment might log 4.7 BTU/s of heat release at peak. To publish in a journal like Combustion and Flame or the Proceedings of the Combustion Institute, the value must convert to watts: 4.7 × 1,055.06 ≈ 4,959 W or 4.96 kW. The conversion is one line of analysis, but skipping it produces submissions that get desk-rejected for unit non-compliance with editorial standards. SI is non-negotiable in research publication.
James Prescott Joule's 1843 paddle-wheel experiments measured the mechanical equivalent of heat — the same factor (~778 ft·lbf/BTU) that anchors the BTU-to-joule and BTU/s-to-watt conversions used here.
Questions
Frequently asked
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