Convert Joules (J) to Btu

1 joule equals 0.000947817 Btu.

Formula: Btu = J × 0.000947817

Joule to Btu Converter

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How to Convert Joule to Btu

1 joule = 0.000947817 Btu

Btu = Joule × 0.000947817

Example: 1 J × 0.000947817 = 0.000947817 Btu

Reverse Conversion

To convert Btu back to Joules:

  • Remember, 1 Btu equals 1055.06 Joules.
  • To convert 0.000947817 Btu to J, multiply 0.000947817 x 1055.06, resulting in 1 J.

Common Joule to Btu Conversions

Joule to Btu (Part 1)
Joule Btu Actions
1 joule 0.000947817 Btu
100 Joules 0.0947817 Btu
500 Joules 0.473909 Btu
1000 Joules 0.947817 Btu
Joule to Btu (Part 2)
Joule Btu Actions
1055 Joules 0.999947 Btu
5000 Joules 4.73909 Btu
10000 Joules 9.47817 Btu

Joules to Btu Conversion Table

Reference table with common joules to btu conversions. All values calculated with high precision.

Joules to Btu Table
1 to 5000

Joules Btu Actions
1 J 0.000947817 Btu
2 12 J 0.00236954 Btu
5 J 0.00473909 Btu
10 J 0.00947817 Btu
25 J 0.0236954 Btu
50 J 0.0473909 Btu
100 J 0.0947817 Btu
250 J 0.236954 Btu
500 J 0.473909 Btu
1000 J 0.947817 Btu
2500 J 2.36954 Btu
5000 J 4.73909 Btu

Joules to Btu Table
10000 to 1 × 109

Joules Btu Actions
10000 J 9.47817 Btu
25000 J 23.6954 Btu
50000 J 47.3909 Btu
100000 J 94.7817 Btu
250000 J 236.954 Btu
500000 J 473.909 Btu
1000000 J 947.817 Btu
2500000 J 2369.54 Btu
5000000 J 4739.09 Btu
10000000 J 9478.17 Btu
2.5 × 107 J 23695.4 Btu
5 × 107 J 47390.9 Btu
1 × 108 J 94781.7 Btu
2.5 × 108 J 236954 Btu
5 × 108 J 473909 Btu
1 × 109 J 947817 Btu

Btu to Joules Table
0.0001 to 12

Btu Joules Actions
0.0001 Btu 0.105506 J
0.00025 Btu 0.263764 J
0.0005 Btu 0.527528 J
0.001 Btu 1.05506 J
0.0025 Btu 2.63764 J
0.005 Btu 5.27528 J
0.01 Btu 10.5506 J
0.025 Btu 26.3764 J
0.05 Btu 52.7528 J
0.1 Btu 105.506 J
14 Btu 263.764 J
12 Btu 527.528 J

Btu to Joules Table
1 to 100000

Btu Joules Actions
1 Btu 1055.06 J
2 12 Btu 2637.64 J
5 Btu 5275.28 J
10 Btu 10550.6 J
25 Btu 26376.4 J
50 Btu 52752.8 J
100 Btu 105506 J
250 Btu 263764 J
500 Btu 527528 J
1000 Btu 1055060 J
2500 Btu 2637640 J
5000 Btu 5275280 J
10000 Btu 1.05506 × 107 J
25000 Btu 2.63764 × 107 J
50000 Btu 5.27528 × 107 J
100000 Btu 1.05506 × 108 J

Definition of Joule

Definition
SI unit of energy: 1 J = 1 N·m = 1 kg·m²·s⁻².
Notes
Used universally in physics, chemistry, and engineering.
Sources
BIPM — SI Brochure

Definition of Btu

Definition
British thermal unit (IT) — legacy heat unit based on heating water.
Reference factor
1 Btu (IT) = 1055.056 J
Sources
EIA — Btu

About the Joule

Facts & Uses

  • SI unit of energy: 1 J = 1 N·m = 1 W·s = 1 C·V = 1 Pa·m³; ubiquitous in mechanics, thermodynamics, electromagnetism, and chemistry.
  • Common engineering scales: kJ, MJ, GJ for fuels, heating/cooling loads, and process energy.
  • Everyday intuition: lifting ~1 N through 1 m ≈ 1 J; a 10 Wh battery stores ≈ 36,000 J for devices/IoT.
  • Key links: 1 kWh = 3.6 × 10⁶ J; 1 eV = 1.602176634×10⁻¹⁹ J (exact) via the fixed elementary charge.

Curiosities

  • Joule heating (I²R) connects electrical losses to thermal energy in conductors and electronics.
  • Although both use N·m, torque (vector, moment) and energy (scalar, work) are physically distinct.
  • Compression/expansion work in gases is often expressed as Pa·m³ (= J), linking pressure–volume integrals to energy.
  • Named for James P. Joule, who quantified the mechanical equivalent of heat, bridging thermal and mechanical domains.

Sources

About the Btu

Facts & Uses

  • Core unit in U.S. HVAC, combustion, and fuel heat content tables; equipment capacity is typically rated in Btu/h (power) for load calculations and furnace/boiler sizing.
  • Common billing/market units: therm (100,000 Btu), MMBtu (106 Btu), and MBH (103 Btu/h) in gas utilities, pipelines, and energy trading.
  • Efficiency metrics convert directly: 1 kWh ≈ 3412 Btu; SEER and HSPF use Btu/Wh; AFUE/boiler efficiency often reported against Btu input.
  • Reference conversion anchor for engineering: 1 Btu (IT) ≈ 1055.06 J ≈ 0.000293071 kWh; useful for energy balances and heat loss/gain estimates.

Curiosities

  • Multiple historical definitions exist (e.g., IT Btu, mean Btu); modern U.S. practice typically standardizes on IT Btu.
  • Ton of refrigeration is a power unit equal to 12,000 Btu/h (not energy) and underpins A/C sizing conventions.
  • Notation can confuse: industry often uses MMBtu for million Btu (Roman numeral convention), while MBtu sometimes means thousand Btu.
  • Building analytics in the U.S. may cite energy use intensity (EUI) as Btu/ft²·yr for benchmarking envelopes and systems.

Sources

Frequently Asked Questions

How many Btu are in one joule?

One joule equals 0.000947817 Btu. To convert, multiply the joule value by 0.000947817. For the reverse, divide the Btu value by 0.000947817 (or multiply by 1055.06).

What is 880 Joules in Btu?

880 Joules = 0.83408 Btu. This is one of the most commonly searched conversions for this pair.

How precise is the joule-to-Btu conversion?

The factor 0.000947817 is accurate to 6 significant figures, derived from international measurement standards. Our calculator uses full precision internally.

Looking for the reverse? Convert Btu to Joule

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Conversion factors verified against NIST, BIPM, ISO 80000-4 1 cal_IT = 4.1868 J by definition (BIPM/ITS-90). Last reviewed: April 2026
Adilson Fernandes By Adilson Fernandes
Tiago Fernandes Reviewed by Tiago Fernandes

All unit conversions on CoolConversion use conversion factors defined or documented by internationally recognised standards bodies (such as ISO and NIST), including both SI and non-SI units.

Popular Energy Conversions

Quick access to frequently searched energy conversions:

1 J→ BTU100 J→ BTU500 J→ BTU1,000 J→ BTU1,055 J→ BTU5,000 J→ BTU10,000 J→ BTU650 J→ BTU880 J→ BTU