Engine Calculator Plus vs Planetary Gear Calculator
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Engine Calculator Plus
Calculate engine specifications for various car and plane engines, including displacement, compression ratio, and horsepower. Supports metric and imperial systems with a user-friendly interface and 3D engine visualization.
- Engine displacement calculation
- Compression ratio calculation
- Horsepower estimation
- Metric and Imperial support
- 3D engine display
- Copyable results
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Engine Calculator Plus is designed to help you figure out engine specs for all car or plane engine types from inline 4 to V12 Engine. This calculator provides calculations for engine displacement based on either the metric or US standard system. Features: - User friendly UI - Engine type selection from single cylinder to complex W16 or even custom cylinder count. - Display 3D engine from selection - Metric or Imperial input - Output Engine Displacement on cc, liter and cubic inch - Output Compression ratio of engine - Calculate estimate horse power in HP and Kilowatts - Include formula to calculate the engine displacement in help page - Result are copy-able to other app The engine's static compression ratio is easily calculated if you know six measurements or volumes: Bore - The diameter of the cylinder bore Stroke - The distance the piston travels in the cylinder Deck Height - The distance between the top of the cylinder bore and the top of the piston, when the piston is at TDC (Top Dead Center, or at its highest position) Piston top volume - If the piston is dished, domed, or dimpled, that has an affect on compression ratio. Combustion chamber volume - How much open space is in the head above the cylinder Compression ratios: Higher compression ratios cylinder produces better power and fuel economy. It is not just because the charge is squeezed harder and the resulting combustion pressure goes up, but also because the higher expansion ratio allows more energy to be extracted from the original high-pressure. High compression ratio engines burn both much more cleanly and much more efficiently than lower-compression engines. However a lower compression motor will let you run cheap fuel, but your motor won't be as efficient, less efficient and less power. *Thanks for your support, stay tune for more update to come.
Planetary Gear Calculator
Calculate gear teeth and speed for planetary gear systems. Quickly simulate how these systems work on the fly, ideal for DIYers designing their own systems before 3D printing. Understand the formulas and components of epicyclic gear systems.
- Calculate gear teeth
- Calculate gear speed
- Simulate planetary gear systems
- Design custom gear systems
- Preview system functionality
- Understand gear formulas
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Planetary Gears Calculator calculate the gear teeth and gear speed of planetary gears system. Plus quickly simulate how the Planetary Gears works on the fly. This is a great tool, especially for DIYer who want to design their own Planetary Gears System quick and easy. Preview how these systems work before 3D print own planetary gear system. Formula for Planetary gear systems: Sun Teeth = ringTeeth - 2 * planetTeeth Planet Teeth = (ringTeeth - sunTeeth) / 2 Ring Teeth = sunTeeth + 2 * planetTeeth ST = sunTeeth PT = planetTeeth RT = ringTeeth SunSpeed = (ST+RT)/ST * PlanetCarrierSpeed - RT/ST * RingSpeed PlanetCarrierSpeed = RT/(ST+RT) * RingSpeed + ST/(ST+RT) * SunSpeed RingSpeed = (ST+RT)/RT * PlanetCarrierSpeed - ST/RT * SunSpeed Planetary gear systems, also known as epicyclic gear systems, are important components in modern engineering. Planetary gear systems are useful for speed variation and commonly found from automatic car transmissions and industrial food mixers to operating tables and solar arrays. There are four core components that make up the planetary gear systems, the ring gear, the sun gear and the planetary gears connected to the carrier. Thanks for your support and do visit nitrio.com for more apps for your iOS devices.
Screenshots
Verdict
The clearest difference is rating: Planetary Gear Calculator at 4.7 against Engine Calculator Plus's 4.0. Planetary Gear Calculator also leads on review sentiment (50% vs 13%) and ratings volume (6 vs 1). Engine Calculator Plus's advantage is chart position (#183 vs unranked) and price ($2.99 vs $3.99). On update cadence, ads, in-app purchases and monetization model 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
Engine Calculator Plus costs $2.99 and Planetary Gear Calculator $3.99 up front. Neither carries in-app purchases, so what you see is what you pay.
Planetary Gear Calculator holds the better App Store score, 4.7 against 4.0. That said, the two scores are not equally well evidenced: Planetary Gear Calculator has 6 ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 13% of Engine Calculator Plus's written reviews are positive against 50% of Planetary Gear Calculator's.
Engine Calculator Plus ships an update every 48 months, Planetary Gear Calculator every 46 months. The most recent releases landed on September 10, 2026 and September 17, 2026 respectively.
| Parameter | Engine Calculator Plus | Planetary Gear Calculator |
|---|---|---|
| Price | $2.99 — better | $3.99 |
| Rating | 4.0 (1 ratings) | 4.7 (6 ratings) — better |
| Positive reviews | 12.5% of reviews | 50.0% of reviews — better |
| Number of ratings | 1 | 6 — better |
| Update frequency | Every 48 months | Every 46 months — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Paid |
| Best chart rank | #183 — better | — |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 13 | 13 |
| Further details — not scored | ||
| Size | 2 MB | 1 MB |
| Age rating | 4+ | 4+ |
| Developer | Nitrio | Heng Jia Liang |
Customer experience
Engine Calculator Plus
Planetary Gear Calculator
In-app purchases
Engine Calculator Plus
No in-app purchases
Planetary Gear Calculator
No in-app purchases
Questions
Is Engine Calculator Plus free?
Is Planetary Gear Calculator free?
Which has better reviews, Engine Calculator Plus or Planetary Gear Calculator?
Do Engine Calculator Plus or Planetary Gear Calculator have ads?
Which is updated more often, Engine Calculator Plus or Planetary Gear Calculator?
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