Calculator
Laundry Detergent Calculator
Most people buy detergent by feel — grab a new bottle when the old one runs low, guess at how long it’ll last. This calculator turns your actual laundry habits into real numbers: how many doses you use a year, how many packs that adds up to, and roughly how often you’ll need to reorder.
Last checked
- Doses per year
- 286 doses
- Packs per year
- 4.5 packs
- Reorder interval
- about 81 days
Would rather not track any of this? STUD can reorder it for you automatically.
How we calculate this
- Loads per week (default)
- We start from ENERGY STAR's figure that the average American family runs about 300 loads a year (≈5.8/week), divide by the Census Bureau's average family size (3.15 people) to get a per-person rate, then multiply by your household size. That derived rate is our own arithmetic, not a figure either source publishes directly — the loads-per-week field is what actually drives every number below, so change it to match your real laundry. ENERGY STAR, "Clothes Washers".
- Average family size
- Used only in the per-person calculation above. US Census Bureau, "America's Families and Living Arrangements".
- One dose per load
- We count one measured dose — however your detergent defines it (a capful, a pod, a scoop) — per load. This is how "dose" is defined for this calculator, not an external claim.
- Machine type
- This doesn't change any number here. HE machines typically call for less detergent per load than standard machines — check the HE fill line on your own product's cap or pods — which is exactly why "loads per pack" is a field you set from your product's label rather than something we assume for a generic HE or standard machine.
- Loads per pack
- Defaults to 64 loads, a common bottle size, purely as a placeholder. Pack sizes vary widely by product and concentration, so there's no figure we could source that would be accurate for your detergent — replace it with the count printed on your own label.
Frequently asked questions
- Why does changing household size sometimes do nothing?
- Household size only sets the suggested default for loads per week. Once you edit loads per week yourself, it stops following household size — the loads-per-week field is what the math actually uses.
- Does machine type change the result?
- No. HE and standard machines typically call for different amounts of detergent per load, but that ratio varies by product, so we don't bake in a number for you. Set "loads per pack" from your own detergent's label instead, and the result will be accurate for your machine and product either way.
- What if my pack size isn't in loads?
- Convert it first. If your label gives ounces or a fixed dose count, divide the total by however much you use per load (in the same unit) to get loads per pack, then enter that number.