Energy Unit: J to kJ Converter

Converter

1 kJ = 1,000 J 1 MJ = 1,000,000 J 1 Wh = 3,600 J 1 kWh = 3,600,000 J

Input value (number)

From

Decimal places

Scientific notation

Trim trailing zeros

Output

Batch Convert

Paste values, one per line (numbers only)

Assume pasted values are

Convert them to

Results

#	Timestamp	Input	From	Output	To	Notes

Tip: Click any value to copy it.

A few ready examples to verify behavior and formatting.

#	Input	From	Output	To	Rationale
1	1500	J	1.5	kJ	Divide joules by 1000
2	0.75	kJ	750	J	Multiply kilojoules by 1000
3	123456	J	123.456	kJ	Decimal handling, three places
4	2.5e4	J	25	kJ	Scientific input acceptable
5	3.2	kJ	3200	J	Unit swap check

Relationship: 1\ \text{kJ} = 1000\ \text{J}

J → kJ: \text{kJ} = \dfrac{\text{J}}{1000}

kJ → J: \text{J} = \text{kJ} \times 1000

Rounding: Apply selected decimal places after conversion; scientific notation optional.

Enter a numeric value and choose source and target units.
Select decimal places; optionally enable scientific notation and trimming.
Click Convert to compute; result appears in the Output field.
Every conversion is logged in the History. Use Download CSV or Download PDF.
For batch operations, paste one value per line, choose units, then click Convert List.
Click any table value to copy. Use Swap Units for quick reversal.

#	J (joule)	kJ (kilojoule)	Note
1	1	0.001	Divide J by 1000
2	10	0.01	Simple scale
3	50	0.05	Simple scale
4	100	0.1	One-tenth kilojoule
5	500	0.5	Half kilojoule
6	1000	1	Exactly one kilojoule
7	2500	2.5	Common example
8	10000	10	Ten kilojoules
9	123456	123.456	Decimal handling
10	2.5e4	25	Scientific input

These relationships help sanity‑check conversions even though this tool focuses on J and kJ.

Prefix	Symbol	Factor	Relation to Joule
Micro	µ	10^-6	1 µJ = 0.000001 J
Milli	m	10^-3	1 mJ = 0.001 J
(Base)	—	1	1 J = 1 J
Kilo	k	10³	1 kJ = 1000 J
Mega	M	10⁶	1 MJ = 1,000,000 J
Giga	G	10⁹	1 GJ = 1,000,000,000 J

Estimates for intuition. Actual values vary by device, model, or conditions.

Scenario	Energy (J)	Energy (kJ)	Notes
60 W lamp for 1 second	60	0.06	Power × time: 60 × 1 s
Smartphone battery, ~15 Wh	54000	54	1 Wh = 3600 J ⇒ 15 Wh = 54 kJ
Dietary Calorie (kcal)	4184	4.184	1 kcal = 4184 J ≈ 4.184 kJ
Kinetic energy, 1 kg at ~10 mph	~10	~0.01	v ≈ 4.47 m/s, KE ≈ ½·m·v² ≈ 10 J
AA battery, ~2 Wh	7200	7.2	2 Wh ≈ 7200 J ≈ 7.2 kJ