What a shave actually costs
The formula, every assumption behind it, and a calculator that uses your prices rather than ours. This is the page the rest of the site's scoring is built on.
By Sawyer V. · Published
The formula
Cost per shave = (blade cost / shaves per blade) + (lather cost per shave) + (hardware cost / lifetime shaves). Every input is either a published pack size, a price you can see today, or a stated assumption you can change. There are no hidden numbers, and there is no score.
The calculator
Put your own prices in
Nothing is pre-filled with a price, because we do not have a price we can stand behind today and a stale one is worse than none. Open the products in another tab, type in what you actually see, and the arithmetic below is done for you. Every assumption is editable and every one of them changes the answer.
The answer
- Double edge, per shave
- Waiting
- Cartridge, per shave
- Waiting
- Double edge, running cost per year
- Waiting
- Cartridge, running cost per year
- Waiting
Enter a blade price and a soap price
Enter a cartridge pack price
At 260 shaves a year, hardware excluded
At 260 shaves a year, handle excluded
Fill in a blade pack price, a soap price and a cartridge pack price and the comparison appears here. We are not going to fill them in for you with numbers we cannot verify today.
Why this page exists
Because running cost is the entire economic argument for leaving cartridge razors, and nobody in this category publishes it. We surveyed the field before building this site: the closest anything came was a price-per-ounce figure on shaving soap, and it did not extend to razors, blades or cartridges.
That is a strange gap, because the arithmetic is not hard. It is division. What makes it awkward is that doing it honestly requires two things most publishers will not do: state your assumptions where a reader can see them, and admit that the price half of the equation is not yours to supply.
Why the arithmetic is split in two
A cost figure has two halves. The first is yield - how many shaves a pack, puck or bottle actually contains. That is published pack size times a stated consumption assumption. It needs no price, it is reproducible from the label, and it is the half nobody publishes.
The second is price, and we cannot supply it. The live price feed on this build is empty, so every buy button on this site reads “Check price” rather than a number we cannot stand behind. A remembered price on a page like this would be worse than useless: you would act on it.
So the calculator above asks you for the prices and we supply everything else. That makes it reproducible rather than authoritative, which is the opposite of a hidden five-point score and is deliberate.
Every assumption, stated
These are the defaults the whole site uses. Each is an assumption rather than a measurement - we have not tested blade life, soap consumption or razor service life - and each is editable in the calculator above.
| Assumption | Default | Where it comes from |
|---|---|---|
| Shaves per week | 5 | Our default working figure; 260 shaves a year |
| Shaves per double-edge blade | 5 | The mid-point of the range commonly given. Not measured by us. |
| Shaves per cartridge | 10 | Makers say 'up to a month' with no shave count. Ten is ours. |
| Grams of soap per lather | 1.5 | Our working figure for a hard soap loaded onto a brush |
| Milliliters per balm or lotion application | 2 | A face-and-neck dose |
| Milliliters per sunscreen application | 1.25 | A face-and-neck dose; roughly two finger-lengths |
| Milliliters per beard oil application | 0.6 | Three to six drops |
| Safety razor service life | 5,200 shaves | Twenty years at the default frequency. An assumption. |
Where the money actually goes: the refill
The single largest cost difference in shaving is not the hardware. It is who sets the price of the refill.
- A double-edge blade is a commodity standard nobody owns. Factories in Russia, Turkey, Japan and elsewhere make blades that fit every safety razor in existence, and they compete on price. No maker can raise it unilaterally.
- A cartridge fits one handle and is made by one company. The handle is cheap because the handle is not the product.
- An electric shaver's head is the same arrangement. Braun's parts guidance is roughly every 18 months, and the price of that is Braun's to set.
That is why refill economics is one of the four axes every product on this site is scored on, and why double-edge blades score the maximum on it while every electric shaver scores low. It is a description of the market rather than a criticism of any one product.
A worked example, with the price left blank
Suppose you buy a hundred Astra blades and a 150 gram tub of soap.
- Blades. 100 blades x 5 shaves each (assumed) = 500 shaves. Blade cost per shave is your pack price divided by 500.
- Lather. 150 g / 1.5 g per lather (assumed) = 100 lathers. Lather cost per shave is your tub price divided by 100.
- Hardware. Razor price divided by 5,200 assumed lifetime shaves, which on any real price is a fraction of a cent.
- Per year. Multiply the total by 260.
Do the same on the cartridge side - pack price divided by (cartridges x 10) - and the difference is your answer. The calculator above does all of it, including how many months of savings pay for the razor.
What this does not capture
Time
A three-pass safety razor shave is five to fifteen minutes; a cartridge shave is two. Nothing on this page prices that, and for some people it is the whole decision. The comparison covers it honestly rather than pretending the cost argument settles everything.
Comfort
Also unpriced, and also real. If a cheaper setup makes your face worse it is not cheaper. Ingrown hairs in particular have a cost that no spreadsheet holds.
The first month
You will get fewer shaves per blade while your technique settles, and you will probably buy a sampler you only half use. Treat the first month's numbers as noise and recalculate in week six with a shave count you measured yourself.
Questions people actually ask
Why do you not just tell me the cost per shave?
Because we would have to invent a price. Prices move weekly, the live price feed on this build is empty, and a cost figure built on a remembered price is a number you would act on. What we can publish honestly is the consumption model, the formula and the assumptions - which is the half of the arithmetic nobody else publishes at all.
How many shaves do you get from a double-edge blade?
We assume five, and we label it as an assumption everywhere it is used because we have not tested blade life. Coarse beards and hard water shorten it; a light beard stretches it. The field is editable above, and after a month of shaving you will have your own number.
How many shaves from a cartridge?
We assume ten. Cartridge makers describe a cartridge as lasting “up to a month” without stating a shave count, and a month at five shaves a week is about twenty, which is optimistic for most beards. Ten is our number and it is ours to defend - change it above if you disagree.
Is a safety razor really cheaper?
Almost always, and the reason is structural rather than marginal: a double-edge blade is a commodity standard many factories make and compete on, while a cartridge fits one handle and is priced by one company. The size of the gap depends on what you currently pay, which is exactly why this is a calculator.
Does this include the razor itself?
The calculator handles it separately, because hardware is a one-off and blades are recurring. Enter the razor price and the tool will tell you roughly how many months of blade savings pay for it. On our assumed twenty-year service life the razor is a rounding error against two decades of blades.