Drilling Calculators
Run real drilling pressure calculations using the exact formulas taught in IWCF and IADC well control certification. Every calculator shows the formula it uses, so you can check the math by hand rather than trusting a number on a screen.
Start Here: Hydrostatic Pressure
Mud weight and depth is the calculation everything else on this page builds on. Type into both boxes and it works out as you go.
That is the static column only. To check it against pore and fracture pressure and get a kick or lost-circulation warning, use the full hydrostatic pressure calculator.
Which Calculator Do You Need?
Most people land here mid-problem. Find your situation:
| Your situation | Use this |
|---|---|
| You need the mud column pressure at a given depth | Hydrostatic Pressure |
| The well is shut in and you have SIDPP recorded | Kill Sheet |
| A report quotes sg or kg/m³ and you work in ppg | Mud Weight Converter |
| You're planning casing points or picking a mud weight | Mud Weight Window |
If you're new to this and not sure which applies, start with the hydrostatic pressure calculator — every other calculation on this page builds on it.
If you would rather work it by hand, the drilling formulas cheat sheet lists the same equations with their units and constants written out.
The Calculators
Hydrostatic Pressure Calculator
Calculate hydrostatic pressure, compare against pore and fracture pressure, and get an instant safe/unsafe status.
Formula: HP = MW × 0.052 × TVD
Open Calculator →Kill Sheet Calculator
Calculate kill mud weight, formation pressure, and initial/final circulating pressure after shutting in on a kick.
Formula: KMW = OMW + (SIDPP ÷ (0.052 × TVD))
Open Calculator →Mud Weight Converter
Convert mud weight between ppg, specific gravity, lb/ft³, kg/m³ and psi/ft, plus pressure and depth. Every field updates as you type.
Formula: psi/ft = ppg × 0.052
Open Converter →Mud Weight Window Calculator
Visualize your safe drilling window between pore pressure and fracture pressure gradients at any depth.
Formula: Pore gradient < MW < Fracture gradient
Open Calculator →Units and Conventions
Every calculator on this page uses oilfield units as standard:
- Mud weight — pounds per gallon (ppg)
- Pressure — pounds per square inch (psi)
- Depth — feet, true vertical depth, not measured depth
- Gradient — psi per foot
The depth distinction matters more than anything else on this list. Hydrostatic pressure depends only on the vertical height of the fluid column, so a deviated or horizontal well can have a measured depth far greater than its TVD while the bottomhole pressure tracks TVD alone. Feeding measured depth into any of these calculators on a deviated well will overstate your pressure, sometimes badly.
Frequently Asked Questions
Where does the 0.052 constant come from?
It converts pounds per gallon into psi per foot. A column of fluid one foot tall over one square inch of area holds 12 cubic inches, which is 12 ÷ 231 = 0.05195 gallons. Multiply mud weight in ppg by that figure and you get the pressure that column exerts in psi per foot. The industry rounds it to 0.052.
Should I use TVD or measured depth?
Always true vertical depth for any pressure calculation. Measured depth is used for pipe volumes, strokes, and lag time — not hydrostatic pressure.
Can I use these during an actual well control event?
No. These are reference and training tools. Live well control decisions belong to your certified well control supervisor working from your company's approved procedures and a physical kill sheet. Use these to study, to check your understanding, or to sanity-check a number after the fact.
Do these match the IWCF and IADC exam formulas?
Yes — the formulas shown are the standard ones taught in well control certification. Working through them by hand and checking against the calculator is a reasonable way to prepare, but no website replaces an accredited course.
Do you support metric units?
Not currently. Everything runs in oilfield units (ppg, psi, ft). For SI work the equivalent hydrostatic constant is 0.0981 when using specific gravity and metres to get bar.
Is my data stored?
No. Every calculation runs client-side in your browser. Nothing is transmitted or saved.