Calculated result
Detailed pressure and head values appear below.
| Measurement | Result |
|---|
Calculation steps
Enter calculation details
Formula used
Pressure depends on density, gravity, and vertical fluid height. The calculator converts every input into consistent SI units. It then returns engineering units for practical comparison today.
One foot of typical water produces about 0.433 PSI. Temperature and local gravity can slightly change this value. Use custom settings when better project accuracy is required.
How to use this calculator
- Select head-to-pressure or pressure-to-head mode.
- Enter the known value and choose its unit.
- Select a preset fluid or enter custom properties.
- Adjust temperature, gravity, reference, and precision settings.
- Press Calculate to review results and calculation steps.
- Copy, print, or download the finished result.
Example calculations
| Fluid | Head | Specific gravity | Approximate pressure |
|---|---|---|---|
| Fresh water | 10 ft | 1.000 | 4.33 PSI |
| Fresh water | 100 ft | 1.000 | 43.30 PSI |
| Seawater | 50 ft | 1.025 | 22.19 PSI |
| Diesel fuel | 30 ft | 0.832 | 10.81 PSI |
| Mercury | 2 ft | 13.546 | 11.73 PSI |
Fluid reference values
These values are general references rather than certified specifications. Actual density changes with temperature, composition, and product grade. Confirm manufacturer data for safety-critical engineering decisions before use.
| Fluid | Density, kg/m³ | Specific gravity |
|---|---|---|
| Fresh water | 998.20 | 0.9982 |
| Seawater | 1,025.00 | 1.0250 |
| Brine | 1,150.00 | 1.1500 |
| Diesel fuel | 832.00 | 0.8320 |
| Gasoline | 745.00 | 0.7450 |
| Hydraulic oil | 870.00 | 0.8700 |
| Crude oil | 850.00 | 0.8500 |
| Ethylene glycol | 1,113.00 | 1.1130 |
| Propylene glycol | 1,036.00 | 1.0360 |
| Mercury | 13,546.00 | 13.5460 |
Frequently asked questions
How many PSI are in one foot of water?
One foot of water produces about 0.433 PSI. The exact result depends on density and gravity. Temperature adjustments provide a more precise water conversion result.
How do you convert feet of head to PSI?
Multiply feet by 0.433 for typical fresh water. Then multiply by the fluid's specific gravity value. This calculator also uses the full hydrostatic pressure equation.
Does fluid type affect pressure?
Yes, denser fluids produce greater pressure at equal heights. Lighter fluids produce less pressure for identical head. Choose the correct fluid before trusting your final result.
What is specific gravity?
Specific gravity compares a fluid's density with water. A value above one indicates a denser fluid. It provides a convenient pressure conversion factor for fluids.
Is 0.433 PSI per foot always accurate?
No, it is a useful water approximation only. Density, temperature, and gravity affect the precise conversion. Use high-precision settings for demanding calculations and documentation.
How many feet of water equal one PSI?
One PSI equals about 2.31 feet of water. The number changes slightly with water density variations. Reverse mode calculates the exact head from pressure entered.
What is the difference between head and pressure?
Head describes the vertical height of a fluid. Pressure describes force applied across a defined area. Fluid density connects these measurements through hydrostatic principles directly.
Can this calculator be used for pumps?
Yes, it can estimate static head pressure relationships. Pump systems also include friction and dynamic losses. Complete pump sizing requires those additional system losses too.
Does pipe diameter affect static head pressure?
Pipe diameter does not change ideal static head pressure. Diameter strongly affects flow velocity and friction losses. Static and flowing conditions must therefore be evaluated separately.
Does temperature change the result?
Temperature can change fluid density and pressure conversion. The built-in adjustment applies specifically to fresh water. Other fluids need verified temperature-density data for accuracy.
Can PSI be converted back into feet of head?
Yes, select pressure-to-head mode from the calculator. Enter pressure, unit, fluid, and reference pressure type. The result includes feet, meters, and supporting conversions.