Thrust Block Size Calculator

Design thrust blocks with confidence today, always. Enter data, pressure, soil strength, and safety factor. Get bearing area, dimensions, and downloads in seconds quickly.

Inputs
Enter pipe, pressure, fitting, and soil details.
Responsive grid: 3 columns large, 2 small, 1 mobile.
Switching units refreshes default fields.
Different fittings create different thrust forces.
Used for elbows. Example: 45°, 90°.
Multiplies thrust force for design.
Inside diameter for best accuracy.
Used for reducers only.
Use operating or test pressure as specified.
Allowable bearing pressure at block face.
Along pipe axis, for volume estimate.
Inside diameter for best accuracy.
Used for reducers only.
Use operating or test pressure as specified.
Allowable bearing pressure at block face.
Along pipe axis, for volume estimate.
Auto mode proposes a rectangular face.
Example: 1.5 means wider than tall.
Leave blank to solve from height.
Leave blank to solve from width.
Reset
Example data
Case Fitting Diameter Pressure Soil capacity Safety Req. face area Suggested face
1 90° Bend 200 mm 700 kPa 150 kPa 1.5 0.220 m² 0.574 m × 0.383 m
2 Tee / Branch 250 mm 600 kPa 200 kPa 1.5 0.221 m² 0.575 m × 0.384 m
3 Reducer 300→200 mm 800 kPa 180 kPa 2.0 0.310 m² 0.682 m × 0.454 m
Examples are illustrative. Confirm inputs, standards, and site conditions.
Formula used
1) Pipe cross‑sectional area
A = π · D² / 4
D is internal diameter.
2) Thrust force (simplified)
P is internal pressure. A is pipe area.
  • Bend: F = P · A · (2 · sin(θ/2))
  • Tee / Branch: F = P · A
  • Dead end: F = P · A
  • Reducer: F = P · (A₁ − A₂)
θ is bend angle in radians.
3) Design thrust force
Fdesign = F · SF
SF is the safety factor.
4) Required bearing face area
Ab = Fdesign / qallow
qallow is allowable soil bearing pressure.
How to use this calculator
  1. Select your unit system and fitting type.
  2. Enter pipe diameter, internal pressure, and soil capacity.
  3. For bends, enter the bend angle in degrees.
  4. Choose auto sizing, or set a face width or height.
  5. Click Calculate to see results above the form.
  6. Use CSV and PDF buttons to save your results.
This tool estimates thrust block face area and dimensions. Verify standards, friction effects, restraint systems, and geotechnical data.

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Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.