The toilet paper math
Does a bidet actually pay for itself?
Usually yes, and faster than people expect. Below is every number that goes into that, including the two that argue against it.
No server, no analytics, no cookies, no signup, no tracking of any kind. Your numbers never leave your device.
Payback
—
to cover the hardware
The hedge
—
never think about it again
Toilet paper is the first shelf to empty in every storm and every scare. A bidet quietly opts you out of that whole genre of problem. The figure above prices the markup you would have paid; it cannot price not having to care.
Every number, including the unhelpful ones
| Paper you stop buying | — | |
|---|---|---|
| Emergency run avoided | — | |
| Water and sewer | — | |
| Subtotal, no guesswork | — | nothing probabilistic here |
| Panic markup dodged estimate | — | |
| Kids find the sprayer year one | — | |
| Net, year one | — | both estimates included |
| Net, every year after | — | the kids have learned |
| Hardware, spread over its life | — | |
| Net over 10 years | — |
What actually moves the needle
Every input nudged ±20%, everything else held still. The long bars are worth arguing about. The short ones are decoration, and you may as well know which is which.
How this works
Paper
The slider is the whole ballgame. Most people still dry with paper, which puts the real range at 60–90%. At 50% the answer usually stays positive, so try it at whatever figure you actually believe.
Fuel
Charging a whole grocery run to toilet paper is the classic way to inflate one of these. Only the extra trip counts here, scaled by the same slider. It lands near a dollar.
Water
Roughly 0.10–0.15 gal (0.4–0.6 L) a use, billed at a rate that includes sewer. The default of three uses a day is about triple reality, and even loaded like that it comes to a few dollars against a few hundred saved.
The two estimates
Each sits on its own row so you can see how much of the total is a guess. The kid incident hits year one only. Payback is walked month by month, so a first-year cost pushes the date back by the right amount.
Not included
Plumbing risk, your time, resale value, septic pump-out intervals, water heating on a warm-water seat, and the environmental case. Septic is real money for rural households and deserves its own math. The hedge has no honest dollar figure, so it stays out of the total.
If you are going to buy one
Three tiers, matched to the hardware cost above. Set one and the whole page recalculates for it — the cheap one pays back in months, the expensive one takes years, and the page will tell you so either way.
-
Attachment, cold water $40–80
Clamps under your existing seat. A wrench and twenty minutes. This is what the defaults assume, and it is the one that pays back fastest.
-
Attachment, warm water $100–160
Same idea, but it tees into the hot line under your sink. No electricity. Worth it in a cold house, and it barely moves the payback.
-
Electric seat $300–600
Heated seat, warm air dryer, remote, the works. Needs an outlet near the toilet. Pays back in years rather than months, which the calculator will happily show you.
Our bias, stated plainly
We have no financial stake in what you decide. If that changes, this paragraph changes with it.
Either way, the honest move is to point at the parts of this page built to work against us. The model refuses to zero your paper. It charges the water and the sewer, at triple the realistic usage. It bills the kid incident to year one instead of quietly spreading it. It shows you which inputs barely matter. Push the slider to 50% and the answer usually still holds.
Nothing on this page reads what you click, and no number here moves depending on whether you buy anything. If the argument only worked when you trusted us, it would not be much of an argument.