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>> Home > All Things RC > Calculators And Converters!
Calculators And Converters!

Speed Calculator

Enter distance and unit:
Enter time: Seconds
Speed is (select units before calculating):

Speed Prediction

Propellor Pitch: mm
Propellor RPM:
Prop Slippage: % =
Prop Slippage Guide
  • Monohull approximately 25%
  • Scale Hydro approximately 20%
  • Rigger approximately 15%

Length converter

Enter length: =

Weight converter

Quantity: =

Current Calculator

Battery mAh:
Run Time: = Amps

Volt Drop

Wire Resistance: = Volts, Volt Drop

Cell Pack Voltage

N Of Cells: = Volts

Cell Pack Duration

Battery mAh:
Discharge Current: = Seconds


Voltage: Volts
= Watts
= Ohms

Propellor Pitch

Prop Diameter: mm
Prop Pitch Ratio: :1 Propellor Pitch = mm

Battery Voltage + Power Under Load

Discharge Current:
Resistance Of Cell: Milli-Ohms
Cell Voltage Under Load = Volts
Pack Voltage Under Load = Volts
Power Output Under Load = Watts

Motor R.P.M.

Boat Speed:
Propellor Pitch: mm
Gear Ratio:
Prop Slippage: % = R.P.M.

Discharger Design

Discharge Current:
Use a Ohm resistor across the battery.
With a power rating of Watts
To gain a bigger power rating in a resistor you can put them into parallel, this with half the resistance and double the wattage.

If for example you wanted 3.4 Ohms 50Watt resistor, you could use two 6.8 Ohm 25Watt resistors in parallel to get the same value.

Charging Time

Charging Current:
This battery will take hours to charge up.

Charging Current

Charge Time: hours.
This battery should be given a current of Amps.
It is recommended that batteries are only given fast charges (below 2 hours) occasionally, as they do start to deteriorate with high charging currents.