Concentrated Soap vs Regular Soap: The Honest Cost-Per-Wash Math

A bottle of supermarket hand soap rings up at about $3.50 and costs roughly a penny and a half per wash. A 3.55 L jug of Power One costs $35.40 and works out to about five cents a wash. If cost per wash were the whole story, this article would end right there and you would buy the supermarket bottle. It is not the whole story — but we are going to put every number on the table, including the ones that do not flatter us, and then tell you plainly which jobs each product is actually for.

What "concentrated" actually means

Most hand soaps you buy at the supermarket are roughly 85–92% water. The active surfactants — the molecules that actually lift oil, dirt and bacteria off your skin — make up only a small slice of what you are paying for. Add a fragrance, a thickener, a preservative, and a colorant, and you have a bottle that is mostly tap water in a plastic pump.

A true concentrate flips that ratio. Power One Soap is roughly 20% water — the remaining 80% is real walnut-shell scrubbers, six skin emollients and USDA bio-based surfactants, with no petroleum solvents.

Here is the part most "concentrated soap" articles get wrong. That difference does not show up as more washes per bottle. It shows up as what a single wash can do. A pump of supermarket soap will not take chain oil, printing ink or brake dust off your hands. That is the trade you are actually making, and it is not a cost trade.

The dose is the whole argument

Power One is dispensed neat — one metered pump, nothing to mix, nothing to dilute. That pump releases about 5 mL, because that is what it takes to carry enough walnut shell to actually scrub with. Supermarket pump soap doses around 1 mL, because all it has to do is lather.

Hold the dose honest and the arithmetic is simple:

• Standard 12 oz pump soap. About 355 mL per bottle at ~1 mL per pump — roughly 250 real-world washes once over-pumping is counted.
• Power One 3.55 L. 3,550 mL at a 5 mL metered dose = 710 washes.
• Power One case of four. 14,200 mL = 2,840 washes.

So one 3.55 L jug replaces roughly three supermarket pump bottles by wash count. Not six, not eight. We would rather print the real multiple than round in our own favour.

Cost per wash — the real numbers

Sticker price is the wrong number; cost per wash is the right one. Here is every figure, including the ones that go against us. U.S. prices, 2026:

• Supermarket pump soap — $3.50 / 250 washes = $0.014 per wash.
• Power One 400 mL — $11.95 / 80 washes = $0.149 per wash.
• Power One 3.55 L — $35.40 / 710 washes = $0.050 per wash.
• Power One case of 4 — $140.50 / 2,840 washes = $0.049 per wash.

Supermarket pump soap is cheaper per wash than Power One at every single size. If your hands are only ever dusty, that is the end of the analysis — go buy the $3.50 bottle with our blessing. The 400 mL is a convenience and trial size, and it is the most expensive way to buy this soap.

The comparison that actually means something is against the products Power One competes with: heavy-duty pumice and scrubber hand cleaners. The obvious one is GOJO NATURAL* ORANGE Pumice (7255-04), sold as 4 × 2,000 mL.

We compare it per litre, not per wash, and the reason is worth a paragraph. A per-wash figure is a price divided by a dose, and GOJO publishes no dose for this product. We used to print one here by assuming their pump delivers the same 5 mL ours does — but one distributor listing implies roughly 2 mL per push, and at 2 mL GOJO would come out cheaper per wash than we do. We withdrew that number rather than keep an assumption that happened to flatter us.

Price per litre assumes nothing. It is a price and a volume, both printed on the case:

• Power One 3.55 L — $35.40 / 3.55 L = $9.97 per litre
• Power One case of 4 — $140.50 / 14.2 L = $9.89 per litre
• GOJO 7255-04 — verified case prices of $113.98 and $120.15 for 8.0 L = $14.25 to $15.02 per litre

On that basis Power One is about 30% cheaper per litre than the cheapest GOJO case price we could verify, while being USDA Certified Bio-Based with no petroleum solvents. What that means per wash depends on how much of each a pump actually delivers, which nobody can tell you without a published dose. And we are still not going to tell you it beats grocery-store soap on price, because it does not.

The environmental side

The dollars are the easy part. Concentrated soap also moves less plastic and less water around the country, which is the other reason it has been the standard at scale for decades.

• Less plastic. One 3.55 L jug covers what about three supermarket pump bottles cover, in one container instead of three — and a wall dispenser you fill is a container you stop buying altogether.
• Less shipping weight. Standard pump soap is 90% water. Shipping water around the country in plastic bottles is, on its face, absurd. A concentrate ships the actives and dilutes at the point of use.
• Less water moved. The water you dilute the concentrate with at your sink came out of your own tap. It never had to be packaged or trucked anywhere.

The U.S. EPA has been pushing concentrated cleaning products through its Safer Choice program for exactly this reason — lower transportation impact, lower packaging waste, identical or better cleaning performance.

When concentrated soap is NOT the right choice

It would be dishonest to pretend concentrate is always the answer. There are three cases where standard pre-diluted hand soap is genuinely the better pick:

1. Face wash. Hand-soap concentrates are formulated for hands — tougher pH, stronger surfactant load. Use a dedicated face wash for your face.
2. Hospital and clinical environments where every wash has to be a specific FDA-cleared antimicrobial formulation. Those products are sold pre-diluted at a regulated active concentration, and you should use them exactly as specified.
3. Hands that never get properly dirty. If the worst thing on your hands is dust, a heavy-duty scrubber cleaner is the wrong tool and the wrong price. A $3.50 bottle of pump soap is the rational choice and costs a third as much per wash.

Where Power One earns its place is the other case entirely: workshops, body shops, print rooms, kitchens, grounds crews, machine shops — anywhere hands come off the job carrying something a lather cannot lift. That is a performance argument, not a savings argument, and we would rather make the one that is true.

There is nothing to dilute

Worth stating plainly, because "concentrate" makes people reach for a measuring jug: Power One is used neat. Whether you are pumping from the 400 mL bottle or refilling a wall unit from the 3.55 L jug, you press once and wash. No mixing, no dilution chart, no water added.

The concentration is in the formula — roughly 20% water instead of 90% — not in something you are expected to thin down at the sink. One metered pump is the working dose.

Once you have read this far, the natural next move is to look at the 12 things you can do with one concentrated formula — because the same concentrate that washes hands also handles dishes, surfaces, floors and a dozen other surfaces with different dilution ratios.

Bottom line

"Concentrated" is a measurable fact about the formula — roughly 20% water instead of 90% — not a promise that it is the cheapest soap in the building. It is not. Supermarket pump soap beats Power One Soap on cost per wash at every size, and if lather is all you need, that is the right buy.

What Power One is for is the wash that lather cannot finish: grease, ink, paint, brake dust, ground-in shop dirt. Against the pumice cleaners built for that job it comes in at about five cents a wash, inside the range those products sell for, with USDA bio-based surfactants and no petroleum solvents. Buy it for what it removes, and buy the 3.55 L or the case rather than the small bottle — that is where the price per wash actually settles down.