Repair or replace: compare costs from today
The optional comparison adds new upfront spending and maintenance to each option's electricity estimate for the same number of days. For a repair scenario, put the repair quote under A and the replacement's purchase and installation costs under B. Use each option's expected power and usage in the electricity inputs above. Upfront and annual maintenance amounts are totals for all units; they are not multiplied by the appliance quantity again.
Maintenance is an estimate spread evenly across the period: annual maintenance × days ÷ 365, rounded once to cents. It does not schedule a repair bill. For example, over 365 days, A with $100 of new repairs, $120 of energy and $36.50 of maintenance totals $256.50. B with $300 upfront, $90 of energy and no maintenance totals $390.00. A is $133.50 lower under those entered assumptions. These are examples, not product prices.
Keep past purchase costs out of both options: they have already been paid. This comparison does not model resale value, financing, future price changes, appliance lifespan or the chance of another breakdown. It assumes both options provide the needed service throughout the selected period. Each new cost accepts $0–$1,000,000 with up to two decimal places; a blank means zero. The electricity result below still covers only energy charges.
Compare a realistic usage pattern
A power rating by itself does not tell you the running cost. The number of hours used, whether the appliance cycles on and off, and your own electricity price all matter. Enter the same comparison period for A and B, but use each appliance's actual hours and power. This is useful when comparing an older device with a replacement, two settings on the same device, or a change in the number of appliances running.
The calculator uses US dollars for costs. It does not provide or assume an electricity tariff. Use the variable energy rate from your own plan: if a rate is quoted as 20 cents per kWh, enter 0.20, not 20. Entering 20 would mean twenty dollars per kWh. When a bill includes several variable per-kWh components, use a combined rate only if those components apply to the same consumption you are comparing.
The calculation
Daily energy in kWh = watts ÷ 1,000 × hours per day × duty cycle ÷ 100 × quantity. Period energy = daily energy × days. Period energy cost = period energy × your USD/kWh rate. Each appliance's cost is rounded to cents once, after the whole period is calculated. The difference compares those rounded period totals.
For example, appliance A draws 1,000 W for two hours a day. At a 100% duty cycle it uses 2 kWh per day. Over 30 days that is 60 kWh, or $12.00 at $0.20/kWh. Appliance B draws 800 W for the same hours, using 48 kWh and costing $9.60. B's estimated energy charge is $2.40 lower for that period. These are arithmetic examples, not current utility prices or product claims.
Duty cycle and measured power
Some appliances draw their rated power only while an internal component is active. A 50% duty cycle means the entered power applies for half of the entered daily hours. It is an assumption you provide, not a value the calculator can determine from the product name. Leave duty cycle blank for 100%, or type the percentage you want to compare.
If you already measured an average power that includes cycling, use that measured watts value with a 100% duty cycle. Otherwise cycling is counted twice and the estimate becomes too low. For equipment with several distinct modes, calculate each mode separately using its own measured power and hours. A single duty cycle does not model startup surges, standby energy at a different wattage, or changing outdoor conditions.
What the result does and does not include
The result is the variable energy charge at one flat rate. It excludes fixed service fees, taxes, demand charges, tier boundaries and time-of-use pricing. A real bill may therefore change by a different amount. It also excludes purchase price, maintenance, lifetime and disposal costs, so a lower electricity cost alone does not establish that replacing a working appliance is cheaper overall.
You can enter zero watts, zero daily hours or a zero rate intentionally. A blank required field is an incomplete input and removes the previous result. Optional quantity is a whole number from 1 to 100. Hours range from 0 to 24, duty cycle from 0% to 100%, watts from 0 to 100,000, and the rate from $0 to $100 per kWh. Values allow up to four decimal places. Compare from 1 to 3,650 whole days using the same usage assumptions throughout.
Compare the cost of this print job
Use the printing comparison for one type of black-and-white, single-sided page, with the same paper size and acceptable quality for both options. One page means one printed side on one sheet. Enter the complete page count for the job, including all copies. A 20-page document printed five times means 100 pages here. Duplex sheets, mixed color pages, binding and different paper grades need their own quotes and are not inferred.
Home cost = new printer purchase + page count × your paper-and-ink cost per page. Print shop cost = fixed order fee + page count × the shop's quoted per-page price. These are costs for the quantity you enter, not a prediction of a printer's lifetime cost or a break-even page count. A lower per-page cost can still have a higher job total when buying a printer adds an upfront expense.
For an arithmetic example, 500 pages at $0.04 of home supplies per page plus a $100 new printer cost $120.00. A shop quote of $0.10 per page plus a $2 order fee costs $52.00, so the shop total is $68.00 lower. If you already own the printer and enter $0 for new purchase, the same home job costs $20.00, which is $32.00 lower than the shop quote. These numbers illustrate the formula and are not current product or service prices.
Enter per-page costs in dollars, not cents: four cents is 0.04. Values may have up to four decimal places so small supply costs are not rounded away for every page. Each full job total is rounded once to the nearest cent, with half a cent rounded up. The displayed difference subtracts those two rounded totals. For example, 100 pages at $0.0049 total $0.49 before any fixed cost; the calculation does not round each page to $0.00.
Use your own expected paper and ink or toner cost. Manufacturer cartridge yields, ink coverage, cleaning cycles, failed pages and actual supply use vary; this tool does not estimate them or guarantee a page yield. It also does not add electricity, labor, delivery, sales tax, maintenance or disposal automatically. Keep the two quotes on a comparable basis and confirm any minimum order, volume discount or extra service fee with the provider. The electricity and repair comparisons above are independent and are not silently added to the printing totals.
Frequently asked questions
Which electricity rate should I enter?
Enter the variable price in US dollars per kWh from your own plan. For 20 cents per kWh, enter 0.20. There is no built-in national average or automatic tariff lookup.
What does duty cycle mean?
It is the percentage of the entered hours spent drawing the entered power. Leave it at 100% for continuous operation, or when the watts are already a measured average. Applying a reduced duty cycle to average watts would count cycling twice.
Is this the full electricity bill?
No. The estimate covers only the energy charge at one flat rate. Fixed charges, taxes, demand charges, tiered rates and time-of-use changes are excluded. Purchase and maintenance costs are also excluded.
Why can different energy totals show the same cost?
Each appliance's period cost is rounded once to the nearest cent. Very small differences can round to the same cost. A zero electricity rate also produces equal costs even when energy use differs.
How does the repair or replacement comparison work?
Open the optional comparison to add new upfront spending and annual maintenance to the same period of electricity costs. Enter totals for all units. Past spending, resale value and financing are excluded.
What does the home versus shop printing comparison include?
It compares the entered number of single-sided black-and-white pages at the same quality. Home cost is any new printer purchase plus pages times your paper-and-ink cost per page. Shop cost is its fixed order fee plus pages times its quoted price. Each total is rounded once to cents. Electricity, tax and shipping are not added automatically.