Diaper Count & Cost Calculator
How many diapers, how many boxes, what it costs, and what the rest of the diaper years will run you. The size chart is in the math section.
| Diapers now | — |
| Current size | — |
| Boxes per month | — |
| Cost per month | — |
| Remaining boxes to training | — |
| Remaining cost to training | — |
| Lifetime total (from birth) | — |
Prices used at your box rate. Store-brand subscription boxes run 25-30¢/diaper, drugstore small packs run 35-45¢.
How the math works
Per-day curve (pediatric/nursing standard, left as default): 9/day at 0-1 mo, 8/day to 3 mo, 7/day to 6 mo, 6/day to 12 mo, 5/day to 18 mo, 4/day after, tapering at training.
Size chart (standard brand weights): Newborn up to 10 lb, Size 1 8-14 lb, Size 2 12-18 lb, Size 3 16-28 lb, Size 4 22-37 lb, Size 5 27 lb+. Buy by weight; age defaults here map months to typical sizes.
Remaining totals integrate the per-day curve from current age to your training age at your box price. Lifetime total runs the same curve from birth.
Provenance: per-day counts are the standard parenting/pediatric figures (newborn 8-10, toddler 4-6); 2026 prices reflect store-brand mega-box listings checked at the big-box channels at 25-30¢/diaper.
Frequently asked questions
How many diapers does a baby use per month?
Newborns go through 8 to 10 a day, which is 250 to 300 a month. By 4 to 8 months it settles around 6 to 7 a day, about 180 to 210 a month. The first two months are the spike, the toddler year is the grind.
How much do diapers cost per month?
At 2026 store prices, about 25 to 30 cents per diaper from large subscription boxes, 35 to 45 cents per diaper at drugstore prices in small packs. A newborn month runs $70 to $100 at store prices, $45 to $70 boxed.
How many sizes of diapers will my baby go through?
Most babies use Newborn (skip it, many outgrow it in 2 weeks), Size 1, Size 2, Size 3, Size 4, and sometimes Size 5/6 for tall toddlers. Buy Newborn in one small pack, buy Size 1 in bulk, and keep moving up by weight, not age.
Are cloth diapers cheaper than disposable?
Cloth totals $800 to $1,400 (kit plus laundry), disposables total $1,700 to $2,600 to potty training. Cloth wins on money, disposables win on daycare rules (many require disposable) and travel. The break-even is roughly the first year.