Why unit price beats sticker price
Package sizes are designed to be hard to compare. A larger bottle can cost more per ounce than a smaller one, and a "mega roll" does not hold the same amount as a regular roll. The unit price, meaning the price divided by the quantity, removes the guesswork. Many stores print it on the shelf label.
Category by category
Laundry and cleaning
Compare per ounce or per load. Concentrated formulas use less per load, so the bottle size alone is misleading. Pods and liquid are easier to compare per load.
Paper products
Compare per sheet or per square foot where shown. Roll sizes such as "double" and "mega" differ by brand and are not directly comparable.
Diapers and wipes
Compare per diaper, and only buy the size your child wears now or will wear soon. Babies outgrow sizes quickly, so a large stockpile can go to waste.
Coffee
Compare per ounce for beans and per pod for single-serve. Whole bean coffee tastes best fresh, so avoid buying more than you will use in a few weeks.
Two series for everyday products
Our guides to everyday products are in two series. Eco Essentials covers how to read green claims and compare prices on paper goods, cleaning, kitchen and pet products. Gentle Essentials covers labels for sensitive skin, from soap and shampoo to baby care and oral care. Some guides, such as laundry, baby care and toilet paper, are in both.
Subscribe & Save: when it is worth it
Amazon's Subscribe & Save and similar autoship programs at other retailers offer a discount in exchange for recurring delivery. They can be a good deal, but a few things are worth checking:
- Compare unit prices. Look at the subscribe price per unit, and compare it with the unit price at your usual store on the same day. The discount only matters if the final price is lower.
- Prices change. A subscription does not always lock the price. Check your upcoming orders now and then.
- Choose a sensible schedule. A delivery every month for something you use up every three months means a growing pile.
- Skip freely. Skipping a delivery or cancelling is usually easy, but check the terms.
We do not show Amazon prices on RipePrice, so for Amazon, check the price on Amazon directly and compare it with the unit prices on our product pages.
A quick routine
- Work out your usual unit price for the things you buy often.
- Buy when the unit price is clearly below it, in the amount you will use.
- For everything else, buy small and wait.
See also: pet supplies · Black Friday 2026 · today's price drops