Free calculators for drag force, hydraulic cylinder sizing, and capstan/belt friction. Essential tools for mechanical engineers working with fluid systems and force transmission.
Drag Force Calculator
Calculate aerodynamic or hydrodynamic drag force for standard shapes. Includes drag coefficients for spheres, cylinders, flat plates, airfoils, and custom Cd values.
Hydraulic Fitting Thread Identifier
Identify any hydraulic fitting by measurement. Enter OD and TPI from your calipers — matches against JIC, NPT, BSPP, BSPT, ORB, ORFS, and Metric DIN 2353. Smart disambiguation narrows results automatically.
Hydraulic Hose Size Selector
Select the right hydraulic hose by flow rate and system pressure. Recommends dash size for optimal velocity, lists compatible SAE and EN hose types with pressure ratings.
Hydraulic Fitting Torque Specifications
Look up torque specs for JIC, NPT, ORB, ORFS, BSPP, and Metric fittings. Values in ft-lbs and N-m with material adjustments for brass and aluminum.
Hydraulic Pressure Drop Calculator
Calculate pressure loss through hydraulic hose using Darcy-Weisbach. Includes flow regime detection, power loss, temperature rise, and size comparison.
Hydraulic Cylinder Calculator
Size hydraulic cylinders for required force output. Calculates bore, rod diameter, extension/retraction forces, flow requirements, and cycle time.
Capstan Equation Calculator
Euler-Eytelwein capstan equation for belt/rope friction. Calculates hold force, tension ratio, and minimum wrap angle.
Fluid Mechanics & Force Analysis
From sizing a hydraulic actuator to estimating wind loads, these calculators cover fundamental force and fluid mechanics problems in mechanical design.
Reference Data
See our Hydraulic Cylinder Force Tables for quick bore/pressure/force lookups.
Need More Power?
*ficient design Professional adds saved projects, branded PDF reports, code reference popups, and batch processing for engineering teams.
Stop looking it up twice — run the numbers and keep the record.
This reference is free forever. When you need to actually calculate, document, and defend the result, do it in the app — then export a clean report you can hand to a reviewer.
- ✓46 engineering calculators, unlimited
- ✓Save & reload every calculation
- ✓Organize work into project folders
- ✓Branded, PE-stamped PDF reports
Free plan, no credit card. Upgrade only when it's paying for itself.