What baby gear costs per year of use, stage by stage

Divide by months in use, not by price

The honest denominator is the number of months an item is actually in service, which for baby gear is rarely the number of months you own it. An infant car seat is outgrown by height at around 12 months in most households; a crib is in nightly use for roughly 30 months before a toddler bed replaces it; a full-size stroller stays useful for roughly 36 months.

Those denominators are small, and that is what makes the per-month figures surprising. A $200 item used for 12 months costs $16.67 a month. A $220 item used for 48 months costs $4.58 a month. The second item costs more and is cheaper, which is the entire point of doing the division before the comparison.

Months in use is also the number you can change. A convertible car seat used rear-facing and then forward-facing covers two stages in one purchase; a crib that converts to a toddler bed extends 30 months to 48 or more. Each of those choices moves the denominator, which does more than any discount does.

The first year, added up honestly

In month one the infant seat, the crib and the stroller are all in service at once. On the example figures above that is $16.67 plus $10.00 plus $7.78, which is $34.45 a month, or $413 across the first 12 months. That is the number worth holding in mind, because it is the one a registry list never shows.

From month 13 the picture changes shape rather than size. The infant seat drops out and a convertible seat at $4.58 a month replaces it, so the durable total falls to about $22.36 a month. The crib falls away at around month 30, and from there the stroller and the car seat are most of what remains.

Buying secondhand moves individual lines sharply. A crib bought used at an example $120 instead of $300 costs $4.00 a month rather than $10.00, and $48 a year rather than $120. The safety guide on this site sets out which items that is reasonable for and which fields on the label decide it.

• Months 1 to 12: infant seat, crib and stroller together, about $34.45 a month on the example prices
• Months 13 to 30: convertible seat, crib and stroller, about $22.36 a month
• A used crib at $120 instead of $300 moves that line from $10.00 to $4.00 a month
• Across the first 12 months the three durables come to about $413 in total

Consumables are the larger number

Diapers are the line that dominates the first two years, and they are priced per unit rather than per month, which hides it. At 8 changes a day and an example 25 cents a diaper, that is $2.00 a day, about $61 a month and about $730 a year. Set against $413 of durables across the same 12 months, the consumable is the larger number by a factor of nearly two.

The rate falls with age rather than staying flat. Eight a day in the first months typically becomes five or six a day by the second year, which on the same example price is about $1.38 a day and $42 a month. Any arithmetic that assumes a constant rate across 36 months overstates the total by several hundred dollars.

This is also where a small unit price change beats a large durable decision. Moving from 25 cents to 20 cents a diaper at 8 a day saves $0.40 a day, about $146 a year, which is more than the whole annual cost of the stroller line above. The consumable-interval calculator on this site takes your own rate and unit price, because 8 a day and 5 a day are different households.

Travel systems, bundles and the handover at month 13

Bundles are priced against the first year and used across three. A travel system at an example $350, where the frame only accepts the infant carrier, needs a second stroller at an example $280 at around month 12: $630 across 36 months, or $17.50 a month.

An infant seat at $200 plus a full-size stroller at $280 that takes an infant-seat adapter is $480 across the same 36 months, or $13.33 a month. The bundle is cheaper at the till and more expensive per month of use, and the field that decides it is whether the chassis takes a toddler seat.

The same test applies to cribs. A crib at $300 used for 30 months is $10.00 a month; the same crib converting to a toddler bed and staying in use for 48 months is $6.25 a month. Convertibility is worth paying for exactly as far as it extends the denominator and no further.

Two children change every line except one

A durable used for a second child has its months in use doubled, and its cost per month halves. The crib at $300 across 30 months becomes $300 across 60 months, which is $5.00 a month and $60 a year. The stroller at $280 across 36 months becomes $3.89 a month if it survives to serve 72.

Consumables do not halve, because each child uses their own. The diaper line simply repeats, and across two children it is the only item in this guide whose total scales directly with the number of children.

That asymmetry is the clearest planning rule in the whole area: spend where the item can be reused and economise where it is consumed. It also explains why a slightly more robust stroller is a defensible purchase for a household expecting a second child and a poor one for a household that is not.

Before you buy

• Write down the months each item will actually be in service before comparing any two prices
• Divide price by months in use, then multiply by 12, for every item on the list
• Add up the durables that will be in service at the same time, rather than the ones bought at the same time
• Count your own diaper rate per day and price it per year before budgeting for equipment
• Ask whether a stroller chassis accepts a toddler seat before paying for a bundle
• Treat convertibility as worth paying for only as far as it extends the months in use
• If a second child is likely, weight the durable lines and leave the consumable line alone

Questions readers ask

Why divide by months rather than by years?

Because baby gear stages are measured in months and several of them are shorter than a year. An infant car seat used for 12 months and a convertible used for 48 cannot be compared annually without hiding the difference. Dividing by months makes the $200 seat at $16.67 and the $220 seat at $4.58 directly comparable.

What do the three big durables cost in the first year?

On the example prices here, the infant seat, the crib and the stroller run together at about $34.45 a month, which is about $413 across 12 months. That is the number to hold against a registry list, because it is the total that is actually in service rather than the total that was bought.

Are diapers really more than the equipment?

On these example figures, yes, by close to a factor of two in the first year: about $730 for diapers at 8 a day against about $413 for the three durables. The rate falls with age, so a projection across 36 months that holds 8 a day constant overstates the real total substantially.

Is a convertible car seat always the cheaper route?

Per month of use it usually is, at $4.58 against $16.67 on the figures here. What it gives up is the carrier function: an infant-only seat lifts out with the child asleep and clicks onto a stroller chassis, and a convertible seat stays in the car. Households doing several short trips a day often pay the higher monthly figure for that.

How much does a second child change the arithmetic?

It halves the per-month cost of every durable that survives, because the months in use double. The crib goes from $10.00 to $5.00 a month and the stroller from $7.78 to $3.89. The diaper line does not change at all, since each child uses their own, which makes it the only item that scales directly with children.

Sources

1. Centers for Disease Control and Prevention — child passenger safety, the stages that set how long each seat is used — checked 2026-11-03
2. Consumer Product Safety Commission — business guidance for carriages and strollers, labeling and date of manufacture requirements — checked 2026-11-03