Knowing how many diapers a baby goes through is the basis for everything else: how many to buy, which pack to choose, how much it will cost and when to order. The numbers change a lot over the first months (a newborn uses twice as many as a one-year-old), so we have gathered the averages by age, per day, per week and per month here, plus the total until potty training. These are reference averages; your baby may use more or fewer, and at the end we explain how to fine-tune the calculation.
Chart: diapers per day, week and month, by age
| Age | Per day | Per week | Per month | Usual size |
|---|---|---|---|---|
| 0 to 1 month | 8 to 10 | 56 to 70 | 250 to 300 | Size 1 (Size 0 if under 2.5 kg) |
| 1 to 3 months | 7 to 8 | 50 to 56 | 210 to 240 | Size 1 and Size 2 |
| 3 to 6 months | 6 | 42 | 180 | Size 2 and Size 3 |
| 6 to 12 months | 5 to 6 | 35 to 42 | 150 to 180 | Size 3 and Size 4 |
| 12 to 24 months | 4 to 5 | 28 to 35 | 120 to 150 | Size 4 and Size 5 |
| 24 to 36 months | 3 to 4 | 21 to 28 | 90 to 120 | Size 5 and Size 6, diaper pants |
All told, a baby uses between 5,000 and 6,000 diapers until potty training, which in Portugal happens on average between 2.5 and 3 years of age. About half of them are used in the first year.
Newborns: why they use so many
In the first weeks the baby feeds every 2 or 3 hours, wees 20 to 30 times a day in small amounts and, if breastfed, poos at many of the feeds. Every poo means a change; so does every wet diaper, because a newborn's skin does not tolerate moisture. Hence the 8 to 10 diapers a day, and hence the 56 to 70 a week that surprises so many parents when they first buy diapers. From the third or fourth week the bowel settles, poos become less frequent and the count goes down. For choosing a diaper at this stage, see how to choose the best newborn diaper.
A 6-month-old baby: the most stable phase
Between 4 and 9 months the routine settles: 5 to 6 diapers a day, one of them at night. This is when it pays to buy large boxes, because usage is predictable and the size (Size 3 or Size 4) lasts several months. Starting solids at around 6 months changes the consistency of the poo, not the number of diapers. If the baby starts sleeping through the night, the night-time diaper becomes the only one worn for 10 to 12 hours and deserves its own attention: see overnight diapers: how to choose.
Children over one year: fewer diapers, but more expensive
From 12 months the bladder holds out for longer and the child goes down to 4 or 5 diapers a day. It looks like a saving, but Sizes 5 and 6 cost 30 to 50% more per unit than Sizes 2 and 3, so monthly spending goes down less than the count. At this stage many families switch to diaper pants during the day (easier to change standing up) and keep classic diapers for the night.
How many diapers each size lasts
This is the calculation that matters when deciding on pack size:
| Size | Typical duration | Diapers used in that size |
|---|---|---|
| Size 0 | 0 to 3 weeks (only some babies) | 0 to 200 |
| Size 1 | 3 to 6 weeks | 250 to 400 |
| Size 2 | 2 to 3 months | 450 to 650 |
| Size 3 | 3 to 5 months | 550 to 900 |
| Size 4 | 6 to 10 months | 900 to 1,500 |
| Size 5 | 6 to 12 months | 700 to 1,500 |
| Size 6 | until potty training | 500 to 1,200 |
In practice: in Size 1 never buy more than one or two medium packs; from Size 2 the large box pays off; in Sizes 3 and 4 boxes of 140 to 250 units are the most efficient purchase you will make. The signs that it is time to change size are in how to choose the right diaper size.
What makes usage go up or down
- Breastfeeding vs bottle: breastfed babies poo more often in the first weeks; from the second month the difference disappears.
- Teething, a virus or antibiotics: any of these can add 2 to 3 diapers a day for a few days. It is wise to have a reserve.
- Nursery: many nurseries change at fixed times, which can increase or decrease the count compared with home. Ask how many diapers they need per week.
- Diaper quality: a diaper that leaks or saturates quickly means changing more often. A better diaper can reduce usage by 1 a day.
- Heat: in summer the baby drinks more and wees more.
How to work out your baby's usage in 3 days
Averages are a starting point; you get your real number like this: over three normal days (no illness or travel), count the diapers used and divide by three. Multiply by 7 for the week and by 30 for the month. Add a 10% margin for bad days. That is the number to use when ordering. A 5-month-old baby who uses 6 a day needs around 200 a month with the margin, in other words a box of 186 plus a small pack, or a box of 248 that lasts five weeks.
From diapers to euros
With monthly usage and the price per diaper, spending is easy to estimate: 180 diapers at €0.30 is €54 a month; 150 diapers at €0.40 is €60. We have done the maths by stage and by brand in how much you spend on diapers per month and in cheap diapers in Portugal. For your baby essentials list, see how many diapers to buy before the birth.
Frequently asked questions
How many diapers does a newborn use per day?
Between 8 and 10 in the first three to four weeks, which means 56 to 70 a week and 250 to 300 in the first month.
How many diapers does a 6-month-old baby use?
About 6 a day, 42 a week and 180 a month, usually in Size 3 or Size 4.
How many diapers does a 1-year-old use per day?
Between 4 and 5, including the night-time one. Per month, 120 to 150 diapers.
How many diapers does a baby use until potty training?
Between 5,000 and 6,000, about half of them in the first year.
Is it normal for my baby to use more than the chart?
Yes, especially in the first weeks, when teething or during a virus. If the difference is large and constant, check whether the diaper is saturating quickly (size or brand) before assuming it is down to your baby.
Summary
A newborn uses 8 to 10 diapers a day, a 6-month-old uses 6 and a 1-year-old uses 4 to 5; in total, that is 5,000 to 6,000 diapers until potty training. Count for three days, add 10% and buy by size: few in Size 1, large boxes from Size 2 onwards. You will find every format in our diaper selection.
