Detergent Cost Sheet
Measure your cap once, mark it, and compare products on cost per wash rather than on the shelf price.
BFCBrilliance · bfcbrilliance.com/tools/laundry-detergent-dosing-calculator
Measure your cap once
- Product
- Bottle size
- Price
- Dose on the label
- What a FULL cap holds
- Difference
- Date measured
- Cap marked? (y/n)
Compare products on cost per wash
| Product | Bottle size | Price | Label dose | COST PER WASH |
|---|---|---|---|---|
The arithmetic
- Washes per bottle
- bottle size ÷ dose
- Cost per wash
- price x dose ÷ bottle size
- Washes per year
- washes per week x 52
- Yearly cost
- cost per wash x washes per year
- Over the label by
- (your dose − label) ÷ label
- ⚠ Compare on
- cost per WASH, not bottle price
- ⚠ The dose itself
- from YOUR bottle, not a website
Getting the dose right
- Dose read off THIS product's label, not the last one's
- Load size matched to the label's own guidance
- Water hardness looked up from your supplier
- A full cap measured in a jug to see what it really holds
- Cap marked at the recommended line
- Cap re-measured after switching products
- Dosing slightly under rather than over when unsure
- Machine run empty on a hot wash occasionally if residue has built up
The cap is not a dose
On many products a full cap holds well above the recommended amount for a normal load, and filling it is what most people do because nothing stops them. Measure it once in a kitchen jug and mark the line. That single minute applies to every wash you run with that product.
More is not cleaner
Past the dose the label specifies, the surfactants are already sufficient for the soil in the load. The extra does not clean - it fails to rinse out, stiffening fabric and building up inside the machine, where it is a common cause of smells. If you are going to be wrong, be wrong slightly under.