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Joules to BTU (J to BTU)

Convert joules to BTU: 1 J = 0.000947817 BTU. Exact conversion factor, formula, 22-row table and worked examples, with JSON API and MCP access.

Formula

1 J = 0.000947817 BTU

BTU = joules × 0.0009478171203 — reverse: joules = BTU × 1055.055853

The factor is derived from the SI definitions of both units (base unit: J) as listed in NIST SP 811; results on this page are shown to 6 significant figures, the API returns up to 12.

Worked examples

Joules to BTU conversion table

Joules (J)BTU (BTU)
10.000947817
20.00189563
30.00284345
40.00379127
50.00473909
60.0056869
70.00663472
80.00758254
90.00853035
100.00947817
150.0142173
200.0189563
250.0236954
300.0284345
400.0379127
500.0473909
750.0710863
1000.0947817
2000.189563
2500.236954
5000.473909
10000.947817

FAQ

How many BTU are in one joule?

1 J = 0.000947817 BTU. The factor comes from the SI definitions of both units (NIST SP 811 / BIPM), so it is exact or correct to at least 10 significant figures.

What is the formula to convert joules to BTU?

Multiply the value in joules by 0.0009478171203: BTU = joules × 0.0009478171203. For example, 5 J = 0.00473909 BTU.

How do I convert BTU back to joules?

Multiply by the inverse factor 1055.055853 (joules = BTU × 1055.055853), or use the BTU-to-joules page.

Related conversions

Machine access

Sources