Convert Watts to BTU per Hour - Power Converter

This converter converts a power value expressed in kilowatts (kW) to British Thermal Units per hour (BTU/h). It is designed for quick, engineering‑grade conversions used in HVAC sizing, energy reporting, and equipment specification.

The tool uses internationally recognized unit definitions to produce a clear numeric result and includes guidance on precision, applicable variants of the BTU definition, and how to interpret results in safety or regulatory contexts.

Updated Nov 23, 2025QA PASS — golden 25 / edge 120Run golden-edge-2026-01-23

Governance

Record 3dc8409688f6 • Reviewed by Fidamen Standards Committee

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Methodology

The conversion is a fixed mathematical relation based on SI and accepted energy units: 1 watt equals 1 joule per second, and the BTU is defined in joules per the international reference. The converter multiplies the input in kilowatts by the exact conversion factor to yield BTU per hour.

Results are presented as a numerical conversion only. Users who require traceable metrology for legal or calibration purposes should use calibrated instruments and reference the primary standards from national measurement institutes and standards organizations listed below.

Worked examples

Example 1: 1.0 kW → 1.0 × 3412.1416326739 = 3412.1416326739 BTU/h (rounded 3412.142 BTU/h).

Example 2: 5.5 kW → 5.5 × 3412.1416326739 ≈ 18,766.779979706 BTU/h (rounded 18,766.78 BTU/h).

F.A.Q.

Which conversion factor does this tool use?

This tool uses the international table definition of the BTU (1 BTU = 1,055.05585262 J) and the SI definition of the watt. The exact factor implemented is 1 kW = 3412.1416326739 BTU/h, with common rounding to 3412.142 for display.

Are there different BTU definitions and does that affect results?

Yes. There are historical and regional BTU variants (for example thermochemical). The international table BTU is the standard used here. If you require a specific historic or industry variant, adjust the factor or consult a standards reference.

How many significant digits should I use for engineering work?

For equipment sizing in HVAC and mechanical engineering, 3 to 5 significant digits are commonly sufficient. For metrology, calibration, or legal reporting, follow the precision and uncertainty guidelines from national measurement institutes and document uncertainty.

Is this conversion appropriate for energy vs power calculations?

This converter translates instantaneous power (kW) to a power rate in BTU per hour (BTU/h). It does not compute energy over time (e.g., kWh to BTU) unless you supply an average power and multiply by time separately.

Do I need to consider regulatory or safety standards when using results?

Yes. Use results within the context of relevant safety and performance standards for your industry. For example, electrical equipment, heating systems, and workplace safety may be subject to national or international standards and regulations. Consult the standards bodies listed in the citations.

Sources & citations

National Institute of Standards and Technology (NIST) — SI Units and unit definitions — https://www.nist.gov/pml/weights-and-measures/si-units
International Organization for Standardization (ISO) — Quantities and units (ISO 80000 series) — https://www.iso.org/standard/30669.html
IEEE Standards Association — Standards and guidelines for electrical units and practice — https://standards.ieee.org
Occupational Safety and Health Administration (OSHA) — Guidance on workplace safety and equipment — https://www.osha.gov
NIST SP 811 — Guide for the Use of the International System of Units — https://www.nist.gov/pml/special-publication-811

Further resources

Related tools

External guidance

Versioning & Change Control

Audit record (versions, QA runs, reviewer sign-off, and evidence).

Record ID: 3dc8409688f6

What changed (latest)

v1.0.0 • 2025-11-23 • MINOR

Initial publication and governance baseline.

Why: Published with reviewed formulas, unit definitions, and UX controls.

Public QA status

PASS — golden 25 + edge 120

Last run: 2026-01-23 • Run: golden-edge-2026-01-23

Engine

v1.0.0

Data

Baseline (no external datasets)

Content

v1.0.0

Governance

Last updated: Nov 23, 2025

Reviewed by: Fidamen Standards Committee (Review board)

Credentials: Internal QA

Risk level: low

Reviewer profile (entity)

Fidamen Standards Committee

Review board

Internal QA

Entity ID: https://fidamen.com/reviewers/fidamen-standards-committee#person

Semantic versioning

MAJOR: Calculation outputs can change for the same inputs (formula, rounding policy, assumptions).
MINOR: New features or fields that do not change existing outputs for the same inputs.
PATCH: Bug fixes, copy edits, or accessibility changes that do not change intended outputs except for previously incorrect cases.

Review protocol

Verify formulas and unit definitions against primary standards or datasets.
Run golden-case regression suite and edge-case suite.
Record reviewer sign-off with credentials and scope.
Document assumptions, limitations, and jurisdiction applicability.

Assumptions & limitations

Uses exact unit definitions from the Fidamen conversion library.
Internal calculations use double precision; display rounding follows the unit's configured decimal places.
Not a substitute for calibrated instruments in regulated contexts.
Jurisdiction-specific rules may require official guidance.

Change log

v1.0.0 • 2025-11-23 • MINOR

Initial publication and governance baseline.

Why: Published with reviewed formulas, unit definitions, and UX controls.

Areas: engine, content, ui • Reviewer: Fidamen Standards Committee • Entry ID: 399c6bc53161