How many btus are in 1 joule?

1 J equals 0.0009478171203 BTU. This is an exact conversion factor defined by NIST.

How do I convert joules to btus?

Multiply the value in J by the conversion factor. For example, 10 J = 0.009478171203 BTU. Use our calculator above for instant results.

Is the joules to btus conversion exact?

Yes, this conversion is mathematically exact based on the international definition of these units (NIST SP 811).

Can I convert joules to btus offline?

Yes! OmniConvert runs entirely in your browser — no internet connection needed after the page loads. Your data never leaves your device, ensuring complete privacy.

What is the difference between joules and btus?

Joules (J) and BTUs (BTU) are both units of energy but belong to different measurement systems. 1 J = 0.0009478171203 BTU. Use the converter above to switch between them instantly.

Joules to BTUs (J → BTU) — Free Online Converter

J → BTU Reference Table

J	BTU
0.001 J	9.478171203e-7 BTU
0.002 J	0.000001895634241 BTU
0.003 J	0.000002843451361 BTU
0.004 J	0.000003791268481 BTU
0.005 J	0.000004739085602 BTU
0.006 J	0.000005686902722 BTU
0.007 J	0.000006634719842 BTU
0.008 J	0.000007582536963 BTU
0.009 J	0.000008530354083 BTU
0.01 J	0.000009478171203 BTU
0.02 J	0.00001895634241 BTU
0.03 J	0.00002843451361 BTU
0.04 J	0.00003791268481 BTU
0.05 J	0.00004739085602 BTU
0.06 J	0.00005686902722 BTU
0.07 J	0.00006634719842 BTU
0.08 J	0.00007582536963 BTU
0.09 J	0.00008530354083 BTU
0.1 J	0.00009478171203 BTU
0.2 J	0.0001895634241 BTU
0.3 J	0.0002843451361 BTU
0.4 J	0.0003791268481 BTU
0.5 J	0.0004739085602 BTU
0.6 J	0.0005686902722 BTU
0.7 J	0.0006634719842 BTU
0.8 J	0.0007582536963 BTU
0.9 J	0.0008530354083 BTU
1 J	0.0009478171203 BTU
1.5 J	0.00142172568 BTU
2 J	0.001895634241 BTU
2.5 J	0.002369542801 BTU
3 J	0.002843451361 BTU
3.5 J	0.003317359921 BTU
4 J	0.003791268481 BTU
4.5 J	0.004265177041 BTU
5 J	0.004739085602 BTU
5.5 J	0.005212994162 BTU
6 J	0.005686902722 BTU
6.5 J	0.006160811282 BTU
7 J	0.006634719842 BTU
7.5 J	0.007108628402 BTU
8 J	0.007582536963 BTU
8.5 J	0.008056445523 BTU
9 J	0.008530354083 BTU
9.5 J	0.009004262643 BTU
10 J	0.009478171203 BTU
11 J	0.01042598832 BTU
12 J	0.01137380544 BTU
13 J	0.01232162256 BTU
14 J	0.01326943968 BTU
15 J	0.0142172568 BTU
16 J	0.01516507393 BTU
17 J	0.01611289105 BTU
18 J	0.01706070817 BTU
19 J	0.01800852529 BTU
20 J	0.01895634241 BTU
25 J	0.02369542801 BTU
30 J	0.02843451361 BTU
35 J	0.03317359921 BTU
40 J	0.03791268481 BTU
45 J	0.04265177041 BTU
50 J	0.04739085602 BTU
55 J	0.05212994162 BTU
60 J	0.05686902722 BTU
65 J	0.06160811282 BTU
70 J	0.06634719842 BTU
75 J	0.07108628402 BTU
80 J	0.07582536963 BTU
85 J	0.08056445523 BTU
90 J	0.08530354083 BTU
95 J	0.09004262643 BTU
100 J	0.09478171203 BTU
120 J	0.1137380544 BTU
125 J	0.11847714 BTU
130 J	0.1232162256 BTU
140 J	0.1326943968 BTU
150 J	0.142172568 BTU
160 J	0.1516507393 BTU
175 J	0.1658679961 BTU
180 J	0.1706070817 BTU
200 J	0.1895634241 BTU
225 J	0.2132588521 BTU
250 J	0.2369542801 BTU
275 J	0.2606497081 BTU
300 J	0.2843451361 BTU
350 J	0.3317359921 BTU
400 J	0.3791268481 BTU
450 J	0.4265177041 BTU
500 J	0.4739085602 BTU
600 J	0.5686902722 BTU
700 J	0.6634719842 BTU
750 J	0.7108628402 BTU
800 J	0.7582536963 BTU
900 J	0.8530354083 BTU
1000 J	0.9478171203 BTU
1200 J	1.137380544 BTU
1250 J	1.1847714 BTU
1500 J	1.42172568 BTU
1750 J	1.658679961 BTU
2000 J	1.895634241 BTU
2500 J	2.369542801 BTU
3000 J	2.843451361 BTU
4000 J	3.791268481 BTU
4500 J	4.265177041 BTU
5000 J	4.739085602 BTU
6000 J	5.686902722 BTU
7000 J	6.634719842 BTU
7500 J	7.108628402 BTU
8000 J	7.582536963 BTU
9000 J	8.530354083 BTU
10000 J	9.478171203 BTU
15000 J	14.2172568 BTU
20000 J	18.95634241 BTU
25000 J	23.69542801 BTU
50000 J	47.39085602 BTU
75000 J	71.08628402 BTU
100000 J	94.78171203 BTU

Values based on NIST SP 811 conversion factors

Why Convert Joules to BTUs?

Converting between joules (J) and btus (BTU) is one of the most common energy conversions. Whether for engineering, cooking, travel, or science, knowing how to quickly convert J to BTU saves time and prevents errors.

Energy conversions from J to BTU are crucial for dietitians, physicists, and engineers. In nutrition, understanding the link between calories and joules helps individuals manage their diet and energy intake effectively. In the power sector, converting between kilowatt-hours and British Thermal Units (BTU) is necessary for sizing heating and cooling systems for homes and offices. Physicists rely on precise energy unit conversions to calculate work, heat, and thermodynamic processes. Whether tracking fitness goals or analyzing home energy bills, accurate conversion empowers users to make better health and financial decisions.

How to Convert Joules to BTUs

To convert joules to btus, use the following formula:

BTU = J × 0.0009478171203

Example: 1 J = 0.0009478171203 BTU

For example, 5 J = 0.004739085602 BTU, 10 J = 0.009478171203 BTU, and 100 J = 0.09478171203 BTU. For larger values, 1000 J = 0.9478171203 BTU. Conversely, 1 BTU = 1055.055853 J. Our calculator above performs this conversion instantly with full precision — no rounding errors.

Common Mistakes to Avoid

Calorie confusion: Food 'Calories' are actually kilocalories (kcal).
Joule scale: 1 kWh is 3.6 million Joules (orders of magnitude difference).
Power vs Energy: mixing up Watts (power) and Watt-hours (energy).

Pro Tips

Food labels: Learn to read kcal; average adult needs ~2000 kcal/day.
Battery capacity: Wh = V * Ah. Useful for comparing different voltage batteries.
Efficiency: Energy cannot be created/destroyed, only converted (with some loss as heat).

What is a Joule?

The joule (J) is the SI derived unit of energy. Defined as the work done by a force of one newton displacing an object by one meter.

Joules are used in science and engineering to measure work, energy, and heat. In nutrition, kilojoules (kJ) are used in many countries instead of calories.

What is a BTU?

British Thermal Unit. Heat to raise 1 lb of water by 1°F.

Standard in the US for HVAC systems.

Joules → BTUs

Joules to BTUs Formula