Water and wastewater · Worked step by step
How much pressure does 150 feet of water make?
If math has never been your thing, you are in the right place. Try it on paper first, then we write it out with you, one small step at a time, and explain every step in plain words so you never lose the thread.
The problem
A tank sits 150 feet above a service point. Ignoring friction, how much pressure does that height make?
Grab a pen and paper first
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Watch it solved, with you
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Press play and I’ll write it out with you, one small step at a time.
Every step gets a plain-words explanation here, so you always know exactly what just happened and why.
The written version, step by step
- 1
Write what you know
height = 150 feet • 1 foot = 0.433 psi
- The water is 150 feet high.
- Every foot makes 0.433 psi.
- Multiply to get the pressure.
- 2
Multiply height by 0.433
pressure = 150 × 0.433 • pressure = 64.95 ≈ 65 psi
- 150 × 0.433.
- 150 × 0.4 is 60, plus a bit more.
- That gives about 65 psi.
Quick trick: 150 × 0.433: think 150 × 0.4 = 60, then add 150 × 0.033 (about 5).
Remember this for good
Each foot of water makes about 0.433 psi, so pressure is the height in feet times 0.433.
Height times 0.433. The higher the water, the more pressure, at 0.433 psi per foot.
Solve it fast next time
- Feet given, psi wanted? Multiply by 0.433.
- Psi given, feet wanted? Multiply by 2.31.
- The psi is always smaller than the feet number.
The answer: About 65 psi.