Free everyday tools

Three common calculations,
without the spreadsheet.

Check a coupon-adjusted total, compare different pack sizes, and estimate a device's electricity use. No account or saved inputs required.

All three tools run in your browser. Nothing you type into these calculators is sent to our server.

Changing currency updates the labels and example electricity rate. It does not convert values or fetch exchange rates.
EVERYDAY TOOL 01

Discount and checkout total

See the amount left after a percentage discount and fixed coupon, then add shipping.

Discount and checkout total
Estimated checkout total$83.00
Product savings
$20.00
Effective product discount
20.0%

The percentage discount is applied first, then the fixed coupon. Shipping is added last.

Stores can apply coupons in a different order or exclude some items. Compare this estimate with the final checkout screen.

EVERYDAY TOOL 02

Unit-price comparison

Convert two pack sizes to the same basis before deciding which one costs less.

Product A
Product B
Comparison basis
Product A is cheaper$0.03/1item
A per basis
$0.33/1item
B per basis
$0.36/1item
Lower by
7.6%

Unit price = final price ÷ quantity × comparison basis.

Include delivery fees and discounts in each final price. Unit price does not compare quality, durability, or how much you actually use.

EVERYDAY TOOL 03

Electricity-use estimate

Estimate energy use from a device's wattage and your daily usage time.

Electricity-use estimate
Estimated cost$5.76
Energy for the period
28.8 kWh
Average per day
0.96 kWh

kWh = watts × devices × hours per day × days ÷ 1,000.

The starting electricity rate is only an example. Replace it with the effective rate from your bill. Tiered pricing, taxes, standby use, and appliance cycling are not included.