How much time and money does an additional child take?

People considering having another child will naturally wonder how much harder their life will be if they have another. What does it mean for your personal freedom? Your attention for your existing children? Your ability to do other work?

I’m not attempting to quantify all the things that come with another child – more snuggles, more uproar, more heartbreak, more life. But I did find some data on parents’ time, money, and happiness with additional children.

The part of this that surprised me was a time diary study showing that parents didn’t spend much more time with additional children. But when I looked at records Jeff and I kept, it showed the same thing.

How much more time does it take?

The amount of additional work doesn’t scale linearly with children — in the words of one mother I talked to who was considering a second child, “I’ve already given up so much of my freedom.” 

But some things do scale. Here’s my breakdown of ways an additional child takes time:

• Time related to pregnancy and birth
• Parental leave you take from work with a new child
• Sleep disruption
• Some additional time caring for them, but not nearly as big a jump as the first child
• If they’re not at the same childcare or school as their siblings, additional commute time
• Routine help with education, medical appointments, etc
• Taking them to activities if they do different activities from their siblings
• Additional chaos (health problems, behavior problems, school problems, etc) some of which last past age 18
• More days when you need to miss work because they’re home sick from daycare or school
• Longer duration of parenting generally. Instead of it lasting ~18 years, it lasts 18 + the age gap from your oldest to youngest child

Passive vs active time

Researchers talk about childcare in terms of “active time” (playing with a child, bathing them, reading to them, etc) vs “passive time” (available but not engaged with the child, e.g. cooking while they play in the next room). 

When you have an additional child, you reset the clock back to the days of intensive parenting. The new baby will need lots of hands-on time.

But at some point the youngest child doesn’t need as much supervision. For me, the shift was most noticeable when the youngest was about 2 and was no longer putting objects in her mouth. There’s still a lot of passive time needed (being nearby and available if they need you) but it overlaps with the passive time you were already providing your older child.

Some of the active time overlaps across children — overseeing bath time or reading for two children is similar to doing it for one.

More time is active rather than passive, and the active time is more active

But there are just more times when your active care is needed. Recently I saw a mother of five children writing: “Just for fun I tried to tally each time someone needs me in an hour. 64 times in a single hour.”

An activity like eating a meal, which might be fairly relaxed time for parents of one older child, requires more active helping with more or younger children because there are more people to spill something, need more of something, or have a dispute with each other.

Laura Vanderkam puts it well: “It is simple math that four children create more chances for disaster than two children. Today was one of those days.” She gives the example of one of her kids needing last-minute homework help, another developing a stomach virus, and another getting injured and needing medical care.

This also affects ability to focus on work — more children means more times when someone is home sick, more doctor’s visits, etc.

Time diary data

Sayer et al 2004, from four sets of time diaries of American parents 1965 – 1998: “the presence of young children [before age ~5] increases mothers’ time in child care by about 36 minutes and married fathers’ time by 15 minutes.” About children 5 and older: “Each additional child is associated with a six-minute-per-day increase in mothers’ child care time  . . . More children are not associated with married fathers’ time with children.”

Six minutes is surprisingly low to me, and zero minutes for fathers even more surprising! But my own time logs bore this out. 

I’m guessing the time diaries undercount the most intensive periods of parenting, because few people (including me) are going to complete a long survey during the busiest periods of their lives.

Sanity-checking with our time logs

Jeff and I have periodically logged our time for a week or two. Here’s the average daily time we spent on the main categories during the logs when we had kids:

Apparently we spent similar amounts of time on childcare as we had more children, but slept a bit less and worked less.

(The sleep category is hours when we’re theoretically in bed, but includes feeding / settling children when they wake up in the night. Much of the other time with our kids is recorded as “family time” — hanging out with both adults and some or all of the children.)

Time from children’s perspective

If the number of children increases but the total amount of time parents spend isn’t increasing that much, there’s certainly less one-on-one adult time per child.

But the children spend more time with each other. If they have compatible interests, this can be great — the nineteenth game of pony birthday party is much more interesting to another child than it is to adults. 

In some families, older siblings take on significant amounts of childcare. I think some amount of this can be good, but I don’t want to lay too much on my older children’s shoulders.

Historical changes in time per child

It’s historically totally normal for children to get little one-on-one attention from an adult. In traditional societies, toddlers are typically watched by an older sibling, or in a little gang of children loosely supervised by whichever relative can most be spared from other work.

Children now typically spend more time with parents than they did even in the more recent past. “In the course of the twentieth century, the total amount of time that children spend in the company of their parents, whether on a dual income or not, has in fact increased.” (Berger summarizing Sayer et al.) This is because of smaller families, fathers spending more time with children, and mothers spending less time on housework and non-parenting activities. 

Personally, I feel like my family would need to get significantly bigger before I felt I was depriving my existing children of a reasonable amount of parental care. And even that level would be what our grandparents considered normal.

Financial cost of additional children

This is one where you’re more able to make some estimates yourself. By putting together information about the cost of the housing, childcare, lost income, and education costs you expect, you’ll get a lot of the picture.

The USDA puts out a periodic report on the cost of raising children, based on an assumption of two children. Their estimate is that an only child costs 27% more than each of the children in a two-child family, and each child in a family with 3 or more children costs 24% less. (This only includes costs to age 18, and doesn’t include higher education.)

Much of this is under your control — richer families spend more on their children, and you can choose to live more like the global 99%. Nearly everyone throughout history has raised their children with less money than you probably have if you’re reading this.

The USDA estimates on childcare costs are an average of families spending very little (because they have a stay-at-home parent) and families spending a lot (because full-time childcare for young children is expensive). Your expected cost of an additional child will vary depending on whether this means lost income or another round of daycare.

Childcare: You get economies of scale if you get a sibling discount at daycare, or if you have one person watching multiple children. If the children are spaced far enough in age, this won’t be the case.

Housing: There may be an economy of scale in housing if you’re already getting a larger place / different neighborhood for your first child. If some of the children share bedrooms, there may not be an increase in housing costs at all. (This is one of the main areas where richer families might spend more.)

Education: if your children’s schooling is free of cost, great. If they’re in private school, there may be an economy of scale if they get a sibling discount. For college, there may be more financial aid to the family in years when multiple children are enrolled.
(My dad says he’s surprised that I didn’t emphasize college more. I kind of figure people are already aware of this one, with uncertainty about what the sticker price will be in 18 years and how much of the sticker price you will actually pay. Looks like US parents pay for half the sticker price on average.)

Stuff: There’s some economy of scale in shared gear (baby gear, toys, clothes especially with same-gender children). But this is a small fraction of overall child-related spending.

Out of necessity, most families spend less per child as they have more children. Car trips become a better deal than airplane trips. The guest room may not be a guest room anymore. Trips to restaurants are more of a hassle and more expensive, so you eat at home more.

To the extent that money can be turned into time, you’ll be able to do that less unless your income is growing faster than your family. Maybe it’s viable to hire extra childcare for the first child or two, but less viable as money is tighter.

Happiness and second children

Here’s FiveThirtyEight analyzing the US General Social Survey:

A year or two into parenting a first child, parents are roughly as happy as they were before. A year or two after the second child, fathers are often feeling better and mothers are often feeling worse. 

That piece also has more on relationship satisfaction and satisfaction with your finances after the first and second child.

Rolling the dice again

The last thing to keep in mind is that each additional child brings the chance for unexpected outcomes. Maybe this one will be the easiest child you’ve raised yet, especially since you have some parenting experience under your belt, or maybe their personality will require a lot of energy from you. Maybe they’ll have serious health problems that require a lot more attention and money than you were expecting.