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Total daily household water
Showers plus toilets plus laundry, all expressed in gallons per day.
The Formula
G = Gs + Gt + Gl
Showers plus toilets plus laundry, all expressed in gallons per day.
| Symbol | Meaning | Unit | Notes |
|---|---|---|---|
| G | Daily total | gal/day | Total indoor water use for the household. |
| Gs | Shower gallons | gal/day | Water used by showers each day. |
| Gt | Toilet gallons | gal/day | Water used by toilets each day. |
| Gl | Laundry gallons | gal/day | Water used by laundry each day. |
What Each Symbol Means
Ggal/day
Daily total
Total indoor water use for the household.
Gsgal/day
Shower gallons
Water used by showers each day.
Gtgal/day
Toilet gallons
Water used by toilets each day.
Glgal/day
Laundry gallons
Water used by laundry each day.
See It Worked With Real Numbers
A formula on its own does not tell you which number goes where. The how to calculate household water usage page applies this equation to a concrete case, shows every intermediate step, and names the mistakes that produce a wrong answer even when the algebra is right.
Where This Formula Appears
This equation is the working core of How To Calculate Household Water Usage, filed under Everyday Life. Every number the guide produces comes from substituting into this one line.