Example 1
- 3 people
- 1 shower
- 8 min
- 9 L/min
- ΔT 28
- 0.92
- grid 350
1.0 kg CO₂e · per year
How much Showers and DHW at 3 people and 8 min? 1.0 kg CO₂e · per year. Grid/1e6, not a gas meter.
Showers and DHW
Type people, showers, minutes, L/min, ΔT, efficiency and grid. 3, 1, 8, 9, 28, 0.92 and 350 give 1.0 kg CO₂e · per year. 2 people give 0.4. 4 and 10 min give 3.6. Typed factors, not a gas meter.
People and minutes. 3 people and 8 min give 1.0 kg CO₂e · per year. Not a gas meter. Empty optional fields stay empty.
Results
Enter data and click Calculate.
How it works
Showers and DHW in this calculator is annual CO₂e from people, minutes and L/min. 3 people, 1 shower, 8 min, 9 L/min, ΔT 28, 0.92, grid 350 give 1.0 kg CO₂e · per year. The second set gives 0.4 kg CO₂e · per year. The third gives 3.6 kg CO₂e · per year.
L/day = people × showers × minutes × L/min. kWh_th = L × ΔT × 0.001163. kWh_el = kWh_th / efficiency. kg/year = kWh_el × grid / 1e6 × 365. The second line on the first set is 2,791 kWh_el.
1.0 kg CO₂e · per year is not a WaterSense mean. 0.4 kg CO₂e · per year is fewer people. 3.6 kg CO₂e · per year is 4 people and 10 min. Optional fields stay empty.
Household CO₂ next door sums kWh and gas. Appliance electricity counts the washer. Here water stays: 3 people and 8 min stay 1.0 kg CO₂e · per year.
Type 3, 1, 8, 9, 28, 0.92 and 350. Then Calculate. 1.0 kg CO₂e · per year. 0.4 kg CO₂e · per year. 3.6 kg CO₂e · per year.
The first set gives 1.0 kg CO₂e · per year. The second gives 0.4 kg CO₂e · per year. The third gives 3.6 kg CO₂e · per year. Other minutes at 3 people change 1.0.
Formula
L/day = people × n × min × L/min. kWh_el = L × ΔT × 0.001163 / efficiency. kg/year = kWh_el × grid / 1e6 × 365. Suffix · per year.
How to use
- Type 3 people, 1 shower and 8 min.
- Add 9 L/min, ΔT 28, efficiency 0.92 and grid 350.
- Click Calculate. The result is 1.0 kg CO₂e · per year.
- 2 people give 0.4. 4 people and 10 min give 3.6 kg CO₂e · per year.
- CO₂e uses 1e6. 2,791 kWh_el sits on the second line.
3 people / 8 min = 1.0 kg CO₂e · per year
People and minutes. 3 people and 8 min give 1.0 kg CO₂e · per year. Not a gas meter.
- Showers
- Minutes and L/min. 8 and 9 leave 1.0 kg CO₂e · per year. 10 and 10 give 3.6.
- DHW
- The heat. 2 people leave 0.4 kg CO₂e · per year. 2,791 kWh_el sits next to it.
- CO₂
- kg × grid/1e6. 3 people stay inside 1.0 kg CO₂e · per year. Not a gas meter.
Examples
Example 2
- 2 people
- 1
- 6 min
- 8 L/min
- ΔT 25
- 0.95
- grid 350
0.4 kg CO₂e · per year
How much at 2 people and 6 min? 0.4 kg CO₂e · per year.
Example 3
- 4 people
- 1.5
- 10 min
- 10 L/min
- ΔT 30
- 0.85
- grid 400
3.6 kg CO₂e · per year
How much at 4 people and 10 min? 3.6 kg CO₂e · per year.
Related calculators
Common questions
How much from 3 people, 8 min and 9 L/min?
1.0 kg CO₂e · per year. 2,791 kWh_el × 350 / 1e6, not a gas meter.
How much at 2 people?
0.4 kg CO₂e · per year. Fewer L/day and 6 min.
How much at 4 people and 10 min?
3.6 kg CO₂e · per year. More L and ΔT 30.
Is 1.0 kg a WaterSense mean?
No. Seven typed fields. A showerhead badge sits outside this calculator.
Where is 2,791 kWh_el?
On the second line. Examples take 1.0 kg CO₂e · per year.
Why so little CO₂e at 2,791 kWh?
The engine divides the grid by 1e6, not 1000.
Does a comma in 0.92 work?
Yes. 0,92 and 0.92 are the same efficiency.
Do blank persons split 1.0?
No. Options stay empty. The result is the year sum.
Is this a heater price?
No. A result from L/min and ΔT. A brand does not enter.
Knowledge sources
The factors on the page are a sketch. Below are EPA emissions terms, not a national inventory.
Page updated in 2026.