How many calories is 1 kJ?

One kilojoule displays as 239.005736138 thermochemical cal or 0.239005736138 thermochemical kcal, using exactly 1,000 J per kJ and 4.184 J per cal. Further inputs give 10 kJ → 2,390.05736138 cal, 100 kJ → 23,900.5736138 cal, 600 kJ → 143,403.441683 cal and 2,000 kJ → 478,011.472275 cal. These are twelve-significant-digit outputs rather than exact terminating decimals.

Is the calorie on this page the same as the Calorie on a food label?

The headline uses the small thermochemical calorie of exactly 4.184 J; the Kilocalorie (kcal) uses exactly 4,184 J. A food Calorie commonly means a kilocalorie, but check the source’s documented convention. For 1,000 kJ, the outputs are 239,005.736138 cal and 239.005736138 kcal. Choose Kilocalorie in To for the latter headline. The converter cannot certify an external food label or infer its definition.

What is the formula for kJ to calories?

For thermochemical units, cal = kJ × 1,000 / 4.184 and kcal = kJ / 4.184. The multiplier 239.005736138 is a rounded approximation to 1,000 / 4.184, so reusing it can change final rounding. In reverse, kJ = cal × 0.004184: 1,000 cal is exactly 4.184 kJ and 100 cal exactly 0.4184 kJ. With Kilocalorie selected, 250 kcal is exactly 1,046 kJ. Exact terminating factors can still produce outputs longer than the twelve-significant-digit display. Swap units reverses the pair and retains the typed scalar.

Which calorie is this, 4.184 joules or 4.1868?

This page uses the thermochemical calorie of exactly 4.184 J. The International Table calorie is a different definition of exactly 4.1868 J, about 0.0669% larger. Under the IT definition 1 kJ would display as 238.845896627 IT cal, compared with 239.005736138 thermochemical cal. Other historical definitions exist. IT and temperature-specific calories are absent from the menus; use a separately specified factor when the source explicitly requires them.

Worked example: a 600 kJ snack and an 8,700 kJ day

For supplied energy quantities under the thermochemical convention, 600 kJ displays as 143,403.441683 cal or 143.403441683 kcal, while 8,700 kJ displays as 2,079,349.9044 cal or 2,079.3499044 kcal. Further supplied values give 500 kJ → 119.502868069 kcal, 1,500 kJ → 358.508604207 kcal and 2,000 kJ → 478.011472275 kcal. These calculations convert the provided numbers; they do not certify a label, a reference intake, an actual food’s energy or a dietary requirement.

How do I convert calories back to kilojoules?

Press the swap button between the boxes and the page becomes calories to kilojoules: 1 cal gives 0.004184 kJ, 100 cal gives 0.4184 kJ and 1,000 cal gives exactly 4.184 kJ. For a stated thermochemical kilocalorie quantity, choose Kilocalorie (kcal) in the From menu after swapping, where 1 kcal is 4.184 kJ and 250 kcal is 1,046 kJ. The factor is exact and finite decimal inputs produce terminating exact values, though the displayed output rounds beyond twelve significant digits.

What else does the page show for 1 kJ?

The same energy in the other common energy units at once: 1,000 J, 239.005736138 cal, 0.239005736138 kcal, 0.277777777778 Wh, 0.000277777777778 kWh and 0.947817120313 IT BTU. The readout strip carries a Show 1 more switch for the uncommon unit, the electronvolt, where 1 kJ reads 6.24150907446e21 eV. Displayed magnitudes below 0.000001 or at 1e15 and above are printed in exponential notation rather than as a row of zeroes.

Why does the page open on kilojoules and calories when I last converted something else?

This focused page opens on Kilojoule and Calorie, while preserving the main converter’s saved unit pair. When storage is usable, a saved value and uncommon-unit preference can travel between pages. Its suffix must still match From. Valid deliberate scalar edits can save those fields after a short delay; invalid or incomplete drafts preserve the saved record. Unusable or conflicting records remain until you use Forget saved settings, which keeps the current conversion on screen. Copy result copies the displayed headline without digit-grouping commas; each visible conversion row has its own Copy button. Displayed and copied values round to twelve significant digits. If native copying fails, a complete selectable summary identifies the input, selected pair and conventions and includes every unit in the category, including uncommon units. Your input and converted values are calculated in the browser and are not uploaded by the converter. The definitions arrive with the page, so conversion needs no external data lookup and keeps working offline after the page has loaded. The core conversion needs no account.

kJ to Calories Converter

Two units share the name calorie, and this page opens on the smaller one. The calorie (cal) in the To box is the thermochemical calorie of exactly 4.184 joules, so kilojoules to calories is cal = kJ × 1,000 / 4.184, which makes 1 kJ 239.005736138 cal, 10 kJ 2,390.05736138 cal and 1,000 kJ 239,005.736138 cal. A food Calorie commonly means a kilocalorie, a thousand small calories under the same definition, and it has its own row in the list under the answer, where the same 1,000 kJ reads 239.005736138 kcal. Check your source’s stated definition; this converter cannot identify a label’s unit convention from context or capitalization. Both directions are short: 1,000 cal is exactly 4.184 kJ, and 4.184 kJ typed into the From box returns exactly 1,000 cal. This page opens with Kilojoule (kJ) in the From box and Calorie (cal) in the To box, ahead of whatever pair the converter last remembered, prints twelve significant digits, and lists the same energy in joules, kilocalories, watt hours, kilowatt hours and IT British thermal units at once. It converts units and nothing else: it knows nothing about what the energy is in and gives no dietary guidance.

From

To239.005736138

Category: Energy

Base unit: joule

Uncommon units: Show 1 more

BTU uses the International Table definition (1,055.05585262 J); cal and kcal are thermochemical (4.184 J per cal). Wh and kWh are energy, not power in W or kW.

Results round to 12 significant digits using the listed unit definitions. Input must have a finite numeric magnitude and at most 512 significant digits. Type a single decimal or scientific number; a matching From unit suffix is accepted. Commas and grouped spaces separate thousands; decimal commas, fractions and compound measurements are refused.

1 kJ in every energy unit

JouleJ
1,000
Caloriecal
239.005736138
Kilocaloriekcal
0.239005736138
Watt hourWh
0.277777777778
Kilowatt hourkWh
0.000277777777778
British thermal unitBTU
0.947817120313

Selectable complete conversion

Unit Converter — Energy
Input: 1 (Kilojoule, kJ)
Result: 239.005736138 cal (Calorie)
Displayed values round to 12 significant digits.
BTU uses the International Table definition (1,055.05585262 J); cal and kcal are thermochemical (4.184 J per cal). Wh and kWh are energy, not power in W or kW.
All other units:
Joule (J): 1000
Calorie (cal): 239.005736138
Kilocalorie (kcal): 0.239005736138
Watt hour (Wh): 0.277777777778
Kilowatt hour (kWh): 0.000277777777778
British thermal unit (BTU): 0.947817120313
Electronvolt (eV): 6.24150907446e21

Common questions

How many calories is 1 kJ?: One kilojoule displays as 239.005736138 thermochemical cal or 0.239005736138 thermochemical kcal, using exactly 1,000 J per kJ and 4.184 J per cal. Further inputs give 10 kJ → 2,390.05736138 cal, 100 kJ → 23,900.5736138 cal, 600 kJ → 143,403.441683 cal and 2,000 kJ → 478,011.472275 cal. These are twelve-significant-digit outputs rather than exact terminating decimals.
Is the calorie on this page the same as the Calorie on a food label?: The headline uses the small thermochemical calorie of exactly 4.184 J; the Kilocalorie (kcal) uses exactly 4,184 J. A food Calorie commonly means a kilocalorie, but check the source’s documented convention. For 1,000 kJ, the outputs are 239,005.736138 cal and 239.005736138 kcal. Choose Kilocalorie in To for the latter headline. The converter cannot certify an external food label or infer its definition.
What is the formula for kJ to calories?: For thermochemical units, cal = kJ × 1,000 / 4.184 and kcal = kJ / 4.184. The multiplier 239.005736138 is a rounded approximation to 1,000 / 4.184, so reusing it can change final rounding. In reverse, kJ = cal × 0.004184: 1,000 cal is exactly 4.184 kJ and 100 cal exactly 0.4184 kJ. With Kilocalorie selected, 250 kcal is exactly 1,046 kJ. Exact terminating factors can still produce outputs longer than the twelve-significant-digit display. Swap units reverses the pair and retains the typed scalar.
Which calorie is this, 4.184 joules or 4.1868?: This page uses the thermochemical calorie of exactly 4.184 J. The International Table calorie is a different definition of exactly 4.1868 J, about 0.0669% larger. Under the IT definition 1 kJ would display as 238.845896627 IT cal, compared with 239.005736138 thermochemical cal. Other historical definitions exist. IT and temperature-specific calories are absent from the menus; use a separately specified factor when the source explicitly requires them.
Worked example: a 600 kJ snack and an 8,700 kJ day: For supplied energy quantities under the thermochemical convention, 600 kJ displays as 143,403.441683 cal or 143.403441683 kcal, while 8,700 kJ displays as 2,079,349.9044 cal or 2,079.3499044 kcal. Further supplied values give 500 kJ → 119.502868069 kcal, 1,500 kJ → 358.508604207 kcal and 2,000 kJ → 478.011472275 kcal. These calculations convert the provided numbers; they do not certify a label, a reference intake, an actual food’s energy or a dietary requirement.
How do I convert calories back to kilojoules?: Press the swap button between the boxes and the page becomes calories to kilojoules: 1 cal gives 0.004184 kJ, 100 cal gives 0.4184 kJ and 1,000 cal gives exactly 4.184 kJ. For a stated thermochemical kilocalorie quantity, choose Kilocalorie (kcal) in the From menu after swapping, where 1 kcal is 4.184 kJ and 250 kcal is 1,046 kJ. The factor is exact and finite decimal inputs produce terminating exact values, though the displayed output rounds beyond twelve significant digits.
What else does the page show for 1 kJ?: The same energy in the other common energy units at once: 1,000 J, 239.005736138 cal, 0.239005736138 kcal, 0.277777777778 Wh, 0.000277777777778 kWh and 0.947817120313 IT BTU. The readout strip carries a Show 1 more switch for the uncommon unit, the electronvolt, where 1 kJ reads 6.24150907446e21 eV. Displayed magnitudes below 0.000001 or at 1e15 and above are printed in exponential notation rather than as a row of zeroes.
Why does the page open on kilojoules and calories when I last converted something else?: This focused page opens on Kilojoule and Calorie, while preserving the main converter’s saved unit pair. When storage is usable, a saved value and uncommon-unit preference can travel between pages. Its suffix must still match From. Valid deliberate scalar edits can save those fields after a short delay; invalid or incomplete drafts preserve the saved record. Unusable or conflicting records remain until you use Forget saved settings, which keeps the current conversion on screen. Copy result copies the displayed headline without digit-grouping commas; each visible conversion row has its own Copy button. Displayed and copied values round to twelve significant digits. If native copying fails, a complete selectable summary identifies the input, selected pair and conventions and includes every unit in the category, including uncommon units. Your input and converted values are calculated in the browser and are not uploaded by the converter. The definitions arrive with the page, so conversion needs no external data lookup and keeps working offline after the page has loaded. The core conversion needs no account.

Results round to 12 significant digits using the listed unit conventions. Many factors are exact definitions; psi and parsec use rounded coefficients. Temperature includes scale offsets. Days and weeks are fixed-duration units, and unit conversion does not determine calendar dates, ambient pressure or a software label’s convention.