How many BTU do space heaters produce? When you get a space heater, you will probably want to know how much heat it can generate (measured in BTU). Electric heaters, however, only have a specified wattage input. Example: 1500 watt space heater.
Here’s the deal:
- Electric heaters have a power input (anywhere from 100W to 20,000W).
- They produce heating output (anywhere from 341 BTU to 68,240 BTU).
Almost 100% of electric power input (wattage) is converted to heating output (BTUs). In reality, about 98% of electricity is converted to heat but for all calculations let’s presume the efficiency is 100%.
If you want to convert watts to BTUs, you only need to know this conversion rule:
1 Watt = 3.412 BTU
Based on this rule, we can tell how many BTU does any electric heater produce.
Example: How many BTU is 1500 watt heater?
Simple. Just multiply 1500W by 3.412 BTU/W like this:
Heater BTUs (1500W) = 1500W × 3.412 BTU/W = 5118 BTU
In short, 1500 watt heater produces 5118 BTU of heating output. This is enough to heat up to 171 sq ft of living area.
To help you out with these calculations, we have prepared 3 useful resources you can freely use, namely:
- Electric Heater BTU Calculator. Here you can just insert the wattage of your heater and the calculator will automatically calculate the amount of heating output (BTUs) this heater generates.
- Electric Heater Wattage To BTU Chart + Coverage Area. We have converted 100W to 20,000W heaters to BTU. On top of that, we have also applied a 30 BTU per sq ft rule of thumb to calculate how many square feet can different wattage heaters heat.
- How many BTUs is 1500W heater? This is an example of how to convert standard 1500 heating watts to BTU and square footage.
Electric Heater Watts To BTU Calculator
Here you can just insert electric heater wattage and get the BTUs (heating output):
Now that you have BTU output, you will probably want to know what size area can such a heater producing this amount of heating output cover.
For this, we can use the simple 30 BTU per sq ft of living space rule and calculate the coverage area. We have calculated all of this (watts to BTU and BTU to sq ft) and gathered the results in the table below:
Electric Heater Wattage To BTU Chart + Coverage Area
| Heater Wattage: | BTUs: | Coverage (30 BTU/Sq Ft): |
| 100 Watts | 341 BTU | 11.4 Sq Ft |
| 200 Watts | 682 BTU | 22.7 Sq Ft |
| 300 Watts | 1024 BTU | 34.1 Sq Ft |
| 400 Watts | 1365 BTU | 45.5 Sq Ft |
| 500 Watts | 1706 BTU | 56.8 Sq Ft |
| 600 Watts | 2047 BTU | 68.2 Sq Ft |
| 700 Watts | 2388 BTU | 79.6 Sq Ft |
| 800 Watts | 2730 BTU | 90.9 Sq Ft |
| 900 Watts | 3071 BTU | 102 Sq Ft |
| 1000 Watts | 3412 BTU | 114 Sq Ft |
| 1250 Watts | 4265 BTU | 142 Sq Ft |
| 1500 Watts | 5118 BTU | 171 Sq Ft |
| 2000 Watts | 6824 BTU | 227 Sq Ft |
| 3000 Watts | 10,236 BTU | 341 Sq Ft |
| 4000 Watts | 13,648 BTU | 455 Sq Ft |
| 5000 Watts | 17,060 BTU | 568 Sq Ft |
| 10,000 Watts | 34120 BTU | 1140 Sq Ft |
| 15,000 Watts | 51,180 BTU | 1710 Sq Ft |
| 20,000 Watts | 68,240 BTU | 2270 Sq Ft |
Using this chart, you can easily figure out how many BTU do different wattage heaters have.
Let’s have a look at the standard 1500 watt heater to illustrate how these calculations are made manually:
How Many BTU Is A 1500 Watt Heater?
1500W is the standard space heater capacity. More than 50% of all space heaters have an electric input of 1500W. Here is how we can calculate how many BTUs is 1500 watts as we have done in the intro:
Heater BTUs (1500W) = 1500W × 3.412 BTU/W = 5118 BTU
Now we can calculate how many sq ft can a 1500 watt heater adequately heat. For heating, we need about 30 BTU per sq ft. Here is how we can determine the square footage 1500 watt heater can cover:
Coverage Area (1500W) = 5118 BTU / 30 BTU Per Sq Ft = 171 Sq Ft
As you can see, a 1500 watt heater can heat up to 171 sq ft of living space.
Hopefully you now understand how to convert watts to BTUs for electric space heaters. If you need any help with the calculations, just use the comment section below and we’ll try to help you out.