Below are some handy conversions for common
measurements used by spa and hot tub owners,
plus other helpful formulas and information. NOTE: Most figures are close
rounded approximations.
amps x volts =
watts volts = amps x resistance (in ohms)
resistance = volts / amps
1000 watts = 1
kilowatt 1 kilowatt hour (kWh) = 1000 watts
used for 1
hour
Estimating the Cost of Power
Consumption
You can calculate the
average operating cost of any electrical appliance by using the
following formula, which multiplies kilowatt hours by the electrical
rate:
kWh x kWh rate = cost (kilowatt hours used x power company rate = cost)
Example:
What is the monthly cost to operate a spa heater rated at 4,000
watts running for 3 hours per day in heating mode, with a local
electrical rate of $0.08 per kilowatt hour?
4 kW x $0.08 rate x 3 hours per day x 30
days = $28.80 per month