能量单位换算器

根据焦耳、卡路里、英热单位和电子伏特的精确定义，将 kWh 换算为 BTU、卡路里换算为焦耳、kcal 换算为 kJ，以及撒姆换算为 kWh。

更新于 2026年9月29日已验证的示例：4

转换后的数值

BTU

有效数字：12；取最近值，等距时远离零

换算: 1 kWh ≈ 3,412.142 BTU
换算系数: 3,412.14163313
精确性: 定义精确，结果为循环小数

1 kWh约为3,412.142 BTU。

用各个单位表示同一个量

1 kWh用各个能量单位表示行数：14

单位	数值	定义
joule (J)	3,600,000	基本单位
千焦 (kJ)	3,600	1 kJ = 1,000 J，精确值
megajoule (MJ)	3.6	1 MJ = 1,000,000 J，精确值
watt-hour (Wh)	1,000	1 Wh = 3,600 J，精确值
kilowatt-hour (kWh)	1	1 kWh = 3,600,000 J，精确值
megawatt-hour (MWh)	0.001	1 MWh = 3,600,000,000 J，精确值
calorie (cal)	860,420.7	1 cal = 4.184 J，精确值（热化学卡路里）
千卡 (kcal)	860.4207	1 kcal = 4,184 J，精确值
British thermal unit (BTU)	3,412.142	1 BTU = 1,055.05585262 J，精确值
therm (US) (thm)	0.03412956	1 thm = 105,480,400 J，精确值
electronvolt (eV)	2.246943 × 10²⁵	1 eV = 1.602176634 × 10⁻¹⁹ J，精确值
erg	36,000,000,000,000	1 erg = 1 × 10⁻⁷ J，精确值
foot-pound (ft·lbf)	2,655,224	1 ft·lbf = 1.3558179483314004 J，精确值
tonne of oil equivalent (toe)	0.00008598452	1 toe = 41,868,000,000 J，精确值

计算方法 S

将kilowatt-hour换算为joule
$1\ \text{kWh} \times 3{,}600{,}000\ \tfrac{\text{J}}{\text{kWh}} = 3{,}600{,}000\ \text{J}$
1 kWh = 3,600,000 J，精确值
将joule换算为British thermal unit
$3{,}600{,}000\ \text{J} \div 1{,}055.05585262\ \tfrac{\text{J}}{\text{BTU}} = 3{,}412.14163313\ \text{BTU}$
1 BTU = 1,055.05585262 J，精确值
合并换算系数
$1\ \text{kWh} = \frac{3{,}600{,}000}{1{,}055.05585262}\ \text{BTU} \approx 3{,}412.14163313\ \text{BTU}$
两个单位的定义都精确，但换算结果为循环小数；结果显示12位有效数字。

关于能量单位换算器

Every energy unit is a fixed number of joules. A kilowatt-hour is exactly 3.6 MJ (1,000 W for 3,600 s), the thermochemical calorie is 4.184 J, and the International Table British thermal unit is 1,055.05585262 J (NIST SP 811), so each factor is a definition rather than a measurement.

The default converts 1 kWh to 3,412.14 BTU, the link between electricity bills and heating or air-conditioning ratings. Food energy is the other everyday use: a food Calorie is a kilocalorie, so a 2,000 kcal day is 8,368 kJ.

Some units share a name but not a size. The International Table calorie (4.1868 J) is 0.07% larger than the thermochemical one used here, and the US therm (105,480,400 J) is defined with the 59 °F BTU, so it comes to 99,976 International Table BTU rather than 100,000.

计算示例

1 kWh in BTU

数值: 1 kWh
从: kilowatt-hour (kWh)
到: British thermal unit (BTU)

转换后的数值: 3,412.14163313 BTU

核验来源：3,600,000 J ÷ 1055.05585262 J (International Table BTU, NIST SP 811 App. B) (Python 3.8 fractions from the legal definitions)

1 kcal in kJ

数值: 1 kcal
从: kilocalorie (kcal)
到: kilojoule (kJ)

转换后的数值: 4.184 kJ
精确性: 精确

核验来源：Thermochemical calorie = 4.184 J exactly (NIST SP 811 App. B)

1 eV in joules

数值: 1 eV
从: electronvolt (eV)
到: joule (J)

转换后的数值: 1.602176634 × 10⁻¹⁹ J

核验来源：e = 1.602176634 × 10⁻¹⁹ C exactly (SI 2019), so 1 eV = 1.602176634 × 10⁻¹⁹ J

1 US therm in BTU

数值: 1 thm
从: therm (US) (thm)
到: British thermal unit (BTU)

转换后的数值: 99,976.1289775 BTU

核验来源：105,480,400 J (NIST SP 811 App. B) ÷ 1055.05585262 J (Python 3.8 fractions from the legal definitions)

常见问题

How many BTU are in a kWh?

3,412.14 BTU. A kWh is 3,600,000 J and the International Table BTU is 1,055.05585262 J, so 3,600,000 ÷ 1,055.05585262 = 3,412.1416. In the other direction 1 BTU is 0.000293071 kWh, so 100,000 BTU of heat is 29.31 kWh.

How many joules are in a calorie?

4.184 J for the thermochemical calorie used here, or 4.1868 J for the International Table calorie; NIST SP 811 lists both. Nutrition labels count kilocalories, often printed as “Calories”, so one food Calorie is 4,184 J or 4.184 kJ. EU food labels give energy in both kJ and kcal.

What is a unit of electricity?

One kilowatt-hour, 3.6 MJ: the energy a 1,000 W appliance uses in one hour. Electricity bills in the UK and India count “units” in kWh, so a 2 kW heater running for 3 hours uses 6 units, and a 10 W LED bulb takes 100 hours to use one.

What is the difference between kW and kWh?

A kilowatt measures power, the rate at which energy is used; a kilowatt-hour measures the energy itself, power multiplied by time. A 3 kW kettle running for 4 minutes uses 3 × 4/60 = 0.2 kWh. Convert kW with the power converter and kWh with this one.

How many kWh are in a therm?

29.3 kWh. The US therm is 105,480,400 J (NIST SP 811), which is 29.3001 kWh; the EU and UK therm, 100,000 International Table BTU or 105,505,585.262 J, is 29.3071 kWh. The two differ by 0.024%, so either rounds to 29.3 kWh.

“能量单位换算器”有多准确？

准确性取决于输入值和方法的假设。十进制运算使用50位有效数字，但估算、数值方法和源数据的精度可能较低；显示时的舍入并不能消除这些限制。已按独立来源核验的计算示例：4。例如，“1 kWh in BTU”根据3,600,000 J ÷ 1055.05585262 J (International Table BTU, NIST SP 811 App. B) (Python 3.8 fractions from the legal definitions)进行核验。

这种方法出自哪里？

NIST SP 811 (2008), Guide for the Use of the SI, Appendix B — conversion factors; NIST Handbook 44, Appendix C — General tables of units of measurement.

关于此计算器

\begin{gathered} x_{\text{to}} = x_{\text{from}} \times \dfrac{f_{\text{from}}}{f_{\text{to}}} \\ f = \text{one unit expressed in } \text{J} \end{gathered}

来源

已对照来源验证

此计算器包含 4 个已解示例，答案来自独立来源。这些示例会在测试套件中运行，你也可以在此运行验证。