Child Support in Washington

Washington Child Support Basics

In Washington State, parents have a legal duty to support their children. Child support ensures a child’s basic needs are met. Your support payments are meant to provide clothing, shelter, food and medical care.

While some areas of family law are vague or complex, child support is relatively easy to understand and straightforward. It’s calculated with a formula issued by the state, which takes into account each parent’s monthly income and the amount of children that need to be supported. 

Because child support is based on a formula, if parents agree on their monthly incomes it can be quickly determined. Afterwards, payment logistics such as how to make payments (check, direct deposit, or through the state) can be worked out. 

Sometimes parents can’t agree on a child support amount. This can happen when a child support order is first issued or years later if there is a change in circumstances. Disputes over child support typically focus on what earnings should be included as income, whether a parent’s income matches their earning potential and if any deviations should apply, which would reduce the amount.

For example, income from a second job can be a point of contention. If you work two jobs, you may be able to exclude income from one if you work more than 40 hours and the second job is only temporary. Similarly, if you have a child from a previous relationship you could request the “Whole Family Deviation,” which would lower the amount you’re obligated to pay because you are already paying support for your other child.

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How much is child support in Washington?

How much you pay in child support will depend on how many children need support and the monthly income of each parent. If you’d like to get an idea for what you will pay follow along with the simple four step child support estimation below. You should be able to plug in your own numbers to ballpark your child support obligation.

1) Determine Gross Monthly Income
2) Calculate Net Income
3) Use Child Support Economic Table
4) Determine Your Proportional Share

Gross Monthly Income

First, determine how much each parent earns per month before taxes. You can use recent pay stubs or tax returns to find this amount. If income is inconsistent, do your best to predict what income will be for the next year. For this sample, we’ll assume the following monthly earnings:

Mother: $5000
Father: $4250

FYI: A parent’s income will not be zero for the calculation. If one parent has not been working or is only working part time you will impute income. This means that you’ll assign an income to them based, on how much they would earn if they were working full time.

Net Income

Second, account for taxes and any other deductions. The primary deduction will be taxes. You can’t just rely on the taxes withheld on your paystubs, since that may not reflect how much you pay in total. This income calculator tool is free and easy to use. Remember, the calculator is based on annual income, so you’ll need to divide the amount by 12. In this case income after taxes equals:

Mother: $4086
Father: $3531

FYI: In addition to taxes, there are other deductions that may apply. One common deduction is a contribution to retirement. You can work with an attorney to identify if any other deductions should be included in your case.

Child Support Economic Table

In total, the mother and father earn $7617 per month after deductions. In order to determine child support, follow this link to see the child support economic tables issued by the state, which start on page 11.

If you scroll to $7600 in monthly income, which is found in the left column you’ll see the follow amounts based on the amount of children:

One child – $1231
Two children – $932 per child
Three children – $745 per child

This is the amount per child that both parents need to cover. If parents only have one child then the total is $1231, but if they have three children the total amount is $2235 = $745 x 3.

Proportional Shares

The last step is to determine your proportional share of support. The proportional share is based on what portion of the total net income you contribute. In this case the total income between the parents was $7617, mother contributed $4086 and father $3531.

Mother: 53.64% = 4086/7617
Father: 46.36% = 3531/7617

Support will be paid to the parent that spends the majority of the time with the children. In this case, let’s assume that the mother is the primary parent and there is one child. Since we determined above that with one child, $1231 is the total amount, the father’s monthly support payment will be $1231 multipled by his proportional share of income (46.36%) or $570.69.

Keep in mind, that this amount just covers the basics of child support. Often parents ask for additional support to cover activities or medical. For example, if a child had been in little league for years the cost of baseball would be added on. How much each parent pays will be based on their proportional share of income. If baseball cost $1000 per year, the father would pay $463.60 per year for baseball in addition to his regular child support amount.

Is child support taxable?

Supporting your child, whether by directly paying an expense or through child support, is not tax deductible. If you receive child support you do not need to claim it as income and if you are paying child support you can’t deduct the payments from your income.

Child support is considered a tax neutral event. However, you may include medical expenses that you pay for your children as an itemized deduction.

The reasoning is that money spent on child support is meant for your children. It is expected that the parent receiving payments will use that money for the essential needs of your child. For example, if you took your child to buy new school clothes you couldn’t expense the cost of clothing. By paying child support you are essentially giving that money for school clothes to the other parent in advance.

How does child support work if you are unemployed?

If a parent is not working a court will assign an income to them. This referred to as imputed income. Effectively, the court will calculate child support based on how much the parent would earn if they were working.

In order to assign an income a court will look at the parent’s level of education, work history, as well as what someone with a similar role makes in the area. For example, if Fred is unemployed in Seattle and has only worked minimum wage jobs in the past a court could use minimum wage in the area to assign a monthly income. This would make Fred’s gross monthly income $2400 = 40 (hours) x 4 (weeks per month) x 15 (dollars per hour).

How does child support work if you are underemployed?

An underemployed parent works less than full time or works a low paying job that they are overqualified for. For example, Jan has worked as a computer programmer at an IT firm for years. After her divorce was filed she quit her job and has been driving a taxi for a living. Her taxi earnings are much less than her previous earnings as a programmer. Because she is capable of earning much more, a court will ignore her recent income as a cab driver and base her child support payments off her income in IT.

When does child support end in Washington State?

In the majority of cases child support will end either when a child graduates from high school or turns 18, whichever occurs later. However, there are a couple common exceptions.

First, a parent can request that a child be supported in college. A child can receive postsecondary support up to age 23. This either can be agreed to by the parents or a parent needs to file a motion with the court to request postsecondary support. Whether the parent’s motion is successful will depend on a list of factors. Unlike child support, which goes to the primary parent, postsecondary support payments go directly to the school, institution, or child.

A second exception occurs when children have special needs. Special needs children can be supported past age 18. Often this will be covered in the original child support order and support should last until a child is self sufficient. If a child is never able to support themselves child support can continue indefinitely.

Learn More About Other Family Law Services


Prenuptial Agreements


Legal Separation

Quit Claim Deeds




Child Support

Name Changes

Spousal Support


Parenting Plans

Unmarried Couples

Domestic Violence


Talk to an attorney to get a free case evaluation.

Talk to an attorney to get a free case evaluation.