A Bidet Pays for Itself in 7 Months — Then Saves Forever
The average American household spends $182/year on toilet paper. A bidet attachment cuts that by about 75%. The math works. It always works. We'll prove it.
Payoff Time
7 mo
Bidet Attachment vs Toilet Paper
Product cost
$79
one-time
Annual savings
$135
vs Toilet Paper
The Setup: Toilet Paper Is an Underrated Expense
Nobody thinks about toilet paper costs because each individual purchase feels trivial — $10 at the grocery store, $25 at Costco. But the Bureau of Labor Statistics Consumer Expenditure Survey puts average American household toilet paper spending at $182/year. For a family of four, that number climbs to $300-400.
You're also buying a product that's 100% designed to be flushed. There's no cheaper version of toilet paper — softer is more expensive, rougher is cheaper, but you're paying either way. The bidet changes the fundamental economics: instead of buying something to throw away, you use water (nearly free) to do 75%+ of the job, then use a small amount of TP to dry.
A bidet attachment — not a full bidet toilet seat, just the kind you install under your existing toilet seat in 15 minutes — costs $30 to $120 depending on features (heated water, air dry, adjustable pressure). Our base case uses the Tushy Spa 3.0 at $79, which includes warm water capability via a T-adapter on your sink line.
The Math: 75% Reduction in TP Use
After installing a bidet, most users report using 1–3 sheets of toilet paper per visit just to pat dry — down from 10–15 sheets. That's roughly a 75–85% reduction. We'll use 75% to be conservative.
$15.17/month in TP × 25% remaining = $3.80/month post-bidet. Monthly savings: $11.37. Bidet water cost is negligible — about 1/8 gallon per use, roughly $1–2/year at US average water rates. Breakeven: $79 ÷ $11.22 = 7.0 months.
| Bidet Attachment | Toilet Paper Only | |
|---|---|---|
| Upfront cost | $79 | $0 |
| Monthly ongoing | $3.95 | $15.17 |
| Month 3 total | $90.85 | $45.51 |
| Month 6 total | $102.70 | $91.02 |
| ★ Breakeven (~7 months) | ~$106 | ~$106 |
| Year 1 total | $126.40 | $182.04 |
| Year 3 total | $221.20 | $546.12 |
| 5-year total | $316.00 | $910.20 |
* All figures are estimates. See methodology for assumptions.
Cumulative Cost Over Time
The lines cross at the breakeven point — that's when the savings zone begins.
The 5-Year Picture: $594 Saved
After five years, you'll have spent about $316 total (the bidet + 5 years of minimal TP) vs. $910 in toilet paper alone. That's a $594 difference on something that requires zero ongoing effort after the initial 15-minute install.
For families of 4, multiply everything by roughly 2.5x. The savings get significant fast. And unlike most "smart" home purchases, a bidet attachment requires no subscription, no app, and no charging.
The Questions Everyone Has
"Is it weird?" For about 2 days. Then it becomes deeply normal and you start wondering why you ever did it the other way.
"Does it splash?" Good bidet attachments have adjustable pressure. Start at the lowest setting. Work up. You'll find your setting.
"Does the water use offset the TP savings?" No. A single toilet paper roll requires 37 gallons of water to produce. A bidet uses about 1/8 gallon per use. The bidet is dramatically more water-efficient, not less.
Sensitivity Analysis: Your Results May Vary
Payoff time changes based on how much you currently spend.
Family of 4, premium TP
You buy Charmin Ultra Soft and go through it fast. $35+/month.
2.6mo
$375/yr
Average household (our base case) (our base case)
$15/month in toilet paper — the US average.
7mo
$135/yr
Single person, frugal TP buyer
You buy bulk TP and use less than average. $8/month in TP.
11.5mo
$51/yr
"A $79 bidet attachment saves $135/year on toilet paper. Payoff: 7 months. After that it's just free clean."
What We Recommend
The main tradeoffs are: cold water vs. warm water, and air-dry vs. pat-dry. Cold-water attachments are cheaper and simpler. Warm-water seats are much more comfortable but cost more and require an electrical outlet nearby.
TUSHY Classic 3.0 Bidet Attachment
$39
upfront
3.5mo
payoff
$135
/ year
Cold water only. No electricity needed. Installs in 15 minutes, no tools required. The fastest payoff of any bidet — and the most popular entry point. Start here.
See on Amazon →Prices updated automatically. Affiliate link.
TUSHY Spa 3.0 Warm Water Bidet
$79
upfront
7mo
payoff
$135
/ year
Connects to your sink's hot water line for a warm wash. No electricity needed (unlike bidet seats). Significant comfort upgrade over cold water for $40 more. Our top pick.
See on Amazon →Prices updated automatically. Affiliate link.
Bio Bidet Slim Zero Electric Bidet Seat
$199
upfront
18mo
payoff
$135
/ year
Full bidet seat replacement. Heated seat, warm water, air dry, adjustable settings. No TP needed at all with the air dry feature. Payoff is longer but the experience is dramatically better.
See on Amazon →Prices updated automatically. Affiliate link.
What we didn't account for
- → Installation. Most attachments need a T-adapter for the warm water line. If you're not comfortable with basic plumbing, add $100-150 for a plumber — that extends payoff by about a year.
- → Bidets aren't for every bathroom. No electrical outlet nearby? Rule out bidet seats. Round toilet shape? Some attachments are oval-only. Measure first.
- → We assumed you still use some TP. If you get the electric seat with air dry, your TP cost drops to nearly $0 — which improves the math even further.