Before you buy it, run the math.
Honest calculators for the eco swaps you're thinking about. No vendor spin, no guilt-tripping — just the real numbers for your household.
See all calculatorsStart with the big three
These are the swaps we get asked about most. Each calculator runs on your actual household numbers.
Bidet vs. toilet paper
See if a bidet actually pays off for your household. Most families break even in 3-6 months.
Run the calculator →Safety razor vs. cartridge
Cartridges cost 4-22x more than safety razors over a lifetime. Find out your exact break-even point.
Run the calculator →Reusable bottle + filter vs. bottled water
If you drink 2 bottles a day, you might be spending more than you think. See the real annual cost.
Run the calculator →How we're different
Math before the pitch
Other "savings calculators" are vendor-owned — they want you to buy their product. We show you the numbers first, honestly, even when the answer is "don't bother."
Your actual household
Every calculator takes real inputs: household size, current prices, usage patterns. A savings number for "the average American" doesn't help you decide.
Transparent assumptions
Every calculator footnotes its sources. You can see and adjust every assumption. No black-box math, no hidden multipliers.