Engine
Electrical power
Real power (kW), apparent power (kVA) and reactive power (kVAr) from the switchboard readings, the current a load will draw, and how loaded a generator is.
Fill in the fields to see the result.
How it works
Three-phase: apparent power S = √3 × V × I (kVA), real power P = S × cos φ (kW), reactive power Q = √(S² − P²) (kVAr). Single phase leaves out the √3. 440 V, 1,000 A at cos φ 0.8 is 762 kVA, 610 kW.
Generators are rated in kVA (current) and kW (engine). Load sharing and the power factor decide how many generators to run; large motors starting draw several times their running current.
For training and cross-checking. Not a substitute for approved navigation equipment, nautical publications and the ship’s own procedures. Calculations run in your browser and nothing you type is stored; a PDF you download is made on our server and not kept.
More tools
All tools- Port to port distances
- Compass error
- Great circle and rhumb line
- Speed, distance, time and ETA
- Current triangle
- Compass error by the sun
- Sunrise, sunset and twilight
- Dead reckoning position
- Distance off
- Sextant altitude and noon latitude
- Required speed for an ETA
- CPA and TCPA
- True wind
- Horizon and light range
- MLC hours of rest
- Ship’s clocks and time zones
- IMO and MMSI number check
- Dock water allowance and loading
- Height of tide
- Mean draught and trim
- GM from rolling period
- Squat and under-keel clearance
- Anchoring
- Search patterns (IAMSAR)
- Fuel consumption and endurance
- Speed and consumption
- Propeller slip
- Indicated power
- Bunker quantity
- Fuel heating temperature
- Cylinder oil feed rate
- Pay and contract dates
- Unit and position converter
- Signal flags and phonetic alphabet
- COLREGs lights and shapes
- Beaufort and sea state scales
- Marine VHF channels