What is the difference between Joules (J) and Watts (W)?

This is a common point of confusion. - Joules (J) measure ENERGY (an amount). - Watts (W) measure POWER (the rate of energy use). They are related: 1 Watt is exactly equal to 1 Joule per second (1 W = 1 J/s). Similarly, BTU measures energy, while BTU/hr measures power.

Joules to BTU (J to BTU) Converter

Q: What is the formula for Joules (J) to BTU?

The formula is: BTU = Joules × 0.000947817. Alternatively, you can divide the number of Joules by 1055.056.

Q: How many Joules are in 1 BTU?

There are 1,055.056 Joules (or 1.055 kilojoules) in 1 British Thermal Unit (BTU).

A dual-purpose scientific converter for **Energy (J, kJ, BTU)** and **Power (W, kW, BTU/hr)**. Enter a value in any field to convert instantly.

Energy Conversion (J ↔ kJ ↔ BTU)

Use this to convert total energy (e.g., thermal energy, battery capacity).

Joules (J)

Kilojoules (kJ)

BTU (British Thermal Units)

Power Conversion (W ↔ kW ↔ BTU/hr)

Use this for appliance ratings (e.g., heaters, AC units). Note: **1 Watt = 1 Joule per second (J/s)**.

Watts (W)

Kilowatts (kW)

BTU per Hour (BTU/hr)

The Key Difference: Energy vs. Power

The most common error in this conversion is confusing **Energy** (measured in Joules or BTU) with **Power** (measured in Watts or BTU/hr).

Energy (Joule, BTU): This is a *total amount* of energy. Think of it like the amount of heat stored in a hot object.
Power (Watt, BTU/hr): This is the *rate* at which energy is used or transferred. A 100-Watt light bulb uses 100 Joules of energy *every second*.

This page provides both calculators. If you are converting a static energy value, use the first calculator. If you are converting an appliance rating (like a heater or AC unit), use the second calculator.

Conversion Formulas

Energy: 1 BTU = 1055.056 Joules (J)
Power: 1 BTU/hr = 0.293071 Watts (W)

To convert from Joules to BTU, you **divide by 1055.056** (or multiply by 0.0009478).

To convert from Watts (J/s) to BTU/hr, you **multiply by 3.41214**.

Common Conversion Chart

Energy (Joule)	Energy (BTU)	Power (Watt)	Power (BTU/hr)
1 J	0.000948 BTU	1 W	3.412 BTU/hr
1,000 J (1 kJ)	0.9478 BTU	1,000 W (1 kW)	3,412 BTU/hr
1,055 J	1 BTU	293 W	1,000 BTU/hr
10,000 J (10 kJ)	9.478 BTU	10,000 W (10 kW)	34,121 BTU/hr
1,000,000 J (1 MJ)	947.8 BTU	1,000,000 W (1 MW)	3,412,141 BTU/hr

Frequently Asked Questions (FAQ)

What is the formula for Joules (J) to BTU?

The formula is: BTU = Joules × 0.000947817. A simpler way is to divide the number of Joules by 1055.056.

How many Joules are in 1 BTU?

There are **1,055.056 Joules** (or 1.055 kilojoules) in 1 British Thermal Unit (BTU).

Is a Watt the same as a Joule?

No. A Joule (J) is a unit of energy. A Watt (W) is a unit of power (energy over time). They are related: **1 Watt = 1 Joule per second (J/s)**.