340 Btu to Joules

340 Btu ≈ 3.5872e+5 J

Calculation: J = 340 Btu × 1055.06 ≈ 3.5872e+5 J

Btu to Joule Converter

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How to Convert Btu to Joule

1 Btu = 1055.06 Joules

Joule = Btu × 1055.06

Example: 340 Btu × 1055.06 = 358720 J

Reverse Conversion

To convert Joules back to Btu:

  • Remember, 1 joule equals 0.000947817 Btu.
  • To convert 358720 J to Btu, multiply 358720 x 0.000947817, resulting in 340 Btu.

340 Btu is also equal to:

  • 358.72 kilojoule
  • 0.099644 kilowatt hour
  • 85.736 calorie (nutritional)
  • 99.644 watt hour
About these units

Btu: British thermal unit (IT) — legacy heat unit based on heating water.

Joule: SI unit of energy: 1 J = 1 N·m = 1 kg·m²·s⁻².

Frequently Asked Questions

How much is 340 Btu in Joules?

340 Btu equals 358720 Joules. This is calculated by multiplying 340 by the conversion factor 1055.06.

What does 340 Btu look like in Joules?

340 Btu (358720 Joules) is heating a cup of water — a kettle uses about 300 Btu.

How do you calculate 340 Btu to Joules?

Multiply 340 by the conversion factor 1055.06. The calculation is 340 × 1055.06 = 358720 Joules. This factor is defined by international measurement standards.

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340 Btu = 358719 Joules
340 Btu = 358719 Joules — conversion chart

For general conversions between Btu and Joules, see the Btu to Joules converter.

Also convert Btu to:

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.