What does it cost to run that appliance?

Three invented appliances, each over 30 days, priced at the next-kWh price above 1,000 kWh on FPL's October 2026 rate and JEA's October 2026 rates with November fuel, before taxes and local fees.

The appliance with the biggest label costs the least here, because it runs for the shortest time. Hours drive the cost as much as watts do: a modest load that never switches off adds up over 720 hours a month. When you're hunting for what's raising a bill, list what runs all day or all night before you look at what draws the most power for a few minutes.

1. Plug the meter into the wall outlet and the appliance into the meter, following the meter's instructions.
2. Leave it through a typical day or two of normal use, long enough to include every way the appliance runs: idle, cycling and full power.
3. Read the kWh the meter has counted and how many hours it has been measuring.
4. Divide kWh by hours and multiply by 1,000 for the average watts. Enter that under "Measured average watts" with 24 hours a day, so no on/off adjustment is applied twice.

A plug-in meter works only for appliances with an ordinary plug. Don't use one with a space heater: the U.S. Fire Administration advises plugging space heaters directly into a wall outlet, so use the space heater calculator's range instead. For equipment that's wired in rather than plugged in, look at your utility's usage data or compare two bills from before and after a change.

Anything that draws power around the clock runs for 8,760 hours a year, so each watt becomes 8.76 kWh. At the price above 1,000 kWh on each utility's current residential rate, before taxes and local fees:

To use the table, measure the draw of something that stays on, or add up several, and read across. Small always-on loads matter because they never stop, not because any one of them is large.

Run the calculator twice, once for the appliance you have and once for the one you're considering, with the same hours and share of time. An invented 150 W compressor appliance running 35% of the time, replaced by a 100 W model with the same pattern, uses 153.3 kWh a year less. At FPL's 14.26¢ above 1,000 kWh that's $21.86 a year, before taxes and local fees.

Put that yearly figure and the price of the new model into the upgrade payback calculator. If the old one still works, the whole price counts against the savings; if it has failed and you'd buy something anyway, only the extra cost of the efficient model does.

Divide the appliance's kWh by the kWh on your bill. The calculator's example, 180 kWh a month, is 15% of an invented 1,200 kWh bill.

What it saves if you use it less depends on where your bill sits against the 1,000 kWh line. On an FPL bill of 1,100 kWh, cutting those 180 kWh takes the bill to 920 kWh: the first 100 come off at 14.26¢ and the rest at 12.26¢, a saving of $24.07 before taxes and local fees. Pricing all 180 kWh at the higher price would have said $25.66.

A sanity check: add up your estimates for the appliances you know about. If they come to more than the kWh on your bill, some hours or shares of time are too high.

• FPL customers: FPL's free Energy Manager shows when, where and how your home uses energy, and its free online Energy Survey gives personalized tips.
• JEA customers: JEA offers a free efficiency assessment: a representative reviews your usage, then does an in-home walk through that covers behaviour and equipment. JEA says no diagnostic equipment is used, and its page doesn't say who qualifies, so ask when you call.
• Anyone: compare kWh per day on two bills from before and after a change, such as a new appliance or a guest staying, with the bill comparison.

• Cents typed as dollars. The price field takes cents: enter 15 for 15¢, not 0.15.
• Hours plugged in instead of hours switched on. For an appliance you turn on and off, count the hours it's on. For one that's always on and cycles by itself, enter 24 hours and set the share of time.
• A guessed share of time. We leave it at 100% rather than guess. A lower number you can't support makes the estimate look better than it is; measure it, or show a range.
• Minutes typed as hours. Enter time as a decimal: 30 minutes is 0.5 hours and 15 minutes is 0.25, not 0.3 or 0.15.
• One of several. Two identical units cost twice as much. Use the "How many" field instead of doubling the hours.
• A summer pattern priced for a year. Run the calculator for the days the appliance is really used, then add up the seasons.

Cost per hour = kWh per hour × price per kWh. Each row assumes the appliance draws that many watts for the whole hour; for anything that cycles on and off, multiply by the share of time it runs. The three prices are examples, so read across to the one closest to yours, or use the calculator above with your exact price.