Comparison

Hydraulic Engineer vs Hydraulic Power Unit

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Hydraulic Engineer

This comprehensive calculator app offers over 1,000 hydraulic engineering formulas across 13 categories. It includes temperature conversions, reference tables, and the ability to save and share calculations. Works offline and supports both US Customary and SI Metric units.

Highlights
  • Over 1,000 hydraulic formulas
  • 13 specialized calculator categories
  • Temperature scale converters
  • Professional reference tables
  • Save and share calculations
  • Works offline
  • US Customary and SI Metric units
Features
Read full description

HYDRAULIC ENGINEER is the most comprehensive hydraulic engineering calculator available on the App Store, featuring over 1,000 formulas across 13 specialized calculator categories, 8 temperature scale converters, and 8 professional reference tables. CALCULATOR CATEGORIES - Actuator Formulas — cylinder force, stroke, speed, and rod calculations - Fluid Power — pressure, flow, horsepower, and torque calculations - Pump Laws — affinity laws for speed, flow, pressure, and power - Vehicle Drive — drive speed, tractive effort, gradeability, and drawbar pull - Hydraulic Tubing — wall thickness, burst pressure, and working pressure - Cylinder Calculations — extend/retract speed, rod end area, and cycle times - Thermal Hydraulics — heat generation, reservoir cooling, heat exchangers, and energy to heat fluid - Oil Velocity & Pressure Loss — pipe velocity, pressure drop per foot, and total system losses - Pipe Flow — Reynolds number, Darcy-Weisbach head loss, laminar friction, and orifice flow - Accumulator Sizing — discharge volume, precharge pressure, adiabatic and isothermal gas volumes - Reservoir Sizing — open/closed circuit sizing, cylinder-based sizing, and oil weight calculations - AC/DC Electrical — Ohm's law, power, resistance, inductance, and motor selection - Area Formulas — 60 geometric area calculations for every common shape 700+ CONVERSION FORMULAS Pressure, horsepower, BTU, flow rates, linear measure, square measure, cubic measure, liquid measure, weights, watts, power, HVAC, metric, sand-to-volume, and fraction conversions. 8 TEMPERATURE SCALES Convert between Celsius, Fahrenheit, Kelvin, Rankine, Reaumur, Newton, Delisle, and Romer — 56 conversion formulas covering every combination. 8 PROFESSIONAL REFERENCE TABLES - Pipe Schedule (Schedule 40 & 80) - ISO Viscosity Grades - Recommended Flow Velocities - Hydraulic Hose Sizing (SAE) - JIC Thread Sizes - Pipe Roughness Values - O-Ring Sizes (AS568) - Wire Rope Working Load Limits KEY FEATURES - Save and share any calculation result - Share reference tables - Calculation history - Favorites for quick access to your most-used formulas - Switch between US Customary and SI Metric units - Dual-unit display shows both US and metric values simultaneously - Dark mode optimized interface - Works offline — no internet connection required PREMIUM UPGRADE Unlock sharing, advanced calculator sections, and unlimited history with a one-time lifetime purchase — no subscriptions. HYDRAULIC ENGINEER is designed for working hydraulic engineers, technicians, maintenance professionals, and engineering students. If there are formulas or reference tables you'd like to see added, just use the built-in feedback feature to let us know.

About

Hydraulic Power Unit

Features
Read full description

The Hydraulic Power Unit Calculator can be used to determine the electrical power required for specific flow and pressure parameters. User can enter values for pump efficiency, oil flow and hydraulic pressure. Calculations will be made to determine required motor power. The user can then select or enter custom power source specifications (Voltage, Single/3 Phase, Power Factor, Motor Efficiency) to determine the amperage draw required. Reservoir design page includes calculations for tank size, oil volume and heat dissipation. Values are entered in either metric or imperial units. Results are shown for both metric and imperial. There is also a Speed - Torque - Power calculator. Enter any two variables and have the third calculated. Unit conversions are built into the calculation page.

Screenshots

Hydraulic Engineer4 screens
Hydraulic Power Unit4 screens

Verdict

The call

The clearest difference is price: Hydraulic Power Unit at Free against Hydraulic Engineer's $4.99. Hydraulic Power Unit also leads on in-app purchases (none vs 1) and iOS requirement (6.0 vs 18.6). Hydraulic Engineer's advantage is update cadence (every 6 months vs every 37 months). On ads and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Hydraulic Power Unit is free to download; Hydraulic Engineer costs $4.99 up front. Hydraulic Engineer sells 1 one-off in-app purchase. Hydraulic Power Unit asks for nothing beyond the download.

UpkeepUpdate frequency

Hydraulic Engineer ships an update every 6 months, Hydraulic Power Unit every 37 months. The most recent releases landed on October 6, 2026 and October 5, 2026 respectively.

Scorecard4 real differences · 6 level
Hydraulic Engineer versus Hydraulic Power Unit: the parameters behind the verdict, then further details
ParameterHydraulic EngineerHydraulic Power Unit
Price$4.99Free — better
Rating4.0 (1 ratings) — better—
Positive reviews25.0% of reviews—
Number of ratings1 — better—
Update frequencyEvery 6 months — betterEvery 37 months
AdsNoNo
In-app purchasesYesNo — better
MonetizationPaid—
DevicesiPhone, iPadiPhone, iPad, iPod — better
Requires iOS18.66.0 — better
Further details — not scored
Size19 MB4 MB
Age rating4+4+
DeveloperHistorycentral.comZanthic Automation Inc.

In-app purchases

1 purchases

Hydraulic Engineer

One-time1
  • Hydraulic Pro$3.99
None

Hydraulic Power Unit

No in-app purchases

Questions

Is Hydraulic Engineer free?
Hydraulic Engineer costs $4.99, and also offers in-app purchases.
Is Hydraulic Power Unit free?
Hydraulic Power Unit is free to download, with no in-app purchases.
Do Hydraulic Engineer or Hydraulic Power Unit have ads?
Neither Hydraulic Engineer nor Hydraulic Power Unit shows ads.
Which is updated more often, Hydraulic Engineer or Hydraulic Power Unit?
Hydraulic Engineer ships an update every 6 months, and Hydraulic Power Unit every 37 months. Most recently, Hydraulic Engineer was updated on October 6, 2026 and Hydraulic Power Unit on October 5, 2026.

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