Tennessee Child Support Calculator: Formula, Income, and Parenting Time

The Tennessee child support calculator is the state’s official worksheet, and it runs on an income shares formula: both parents’ gross monthly incomes are combined, a base support obligation is pulled from a published schedule (keyed to that combined income and the number of children), and each parent is responsible for their proportional share. Health insurance, childcare, and parenting time then adjust the number up or down. At $5,000 in combined adjusted gross monthly income, the base obligation is about $893 for one child and $1,145 for two.¹

How the Formula Works

The premise is that children should receive the same share of parental income they would have if the parents lived together. Both incomes go into one pot. The state schedule converts that combined figure and the number of children into a total support obligation. Each parent then owes their percentage of that total: a parent who earns 60% of the combined income is responsible for 60% of the obligation.¹

The custodial parent is assumed to spend their share directly on the child through daily costs, so the alternate residential parent typically writes the check for the difference.

What Counts as Income

Gross income is broad. Tennessee includes wages, salaries, commissions, tips, bonuses, overtime, self-employment earnings, severance, pensions, Social Security and VA disability, workers’ compensation, unemployment, interest, dividends, trust income, capital gains, rental income, alimony received from someone outside the case, lottery winnings, prizes, and cash gifts or inheritances.² A new spouse or partner covering your housing can also be counted, because it reduces your living expenses.

Military Allowances

Basic Allowance for Housing, Basic Allowance for Subsistence, and Variable Housing Allowances all count as income for support purposes, even though they are not taxed federally.²

Self-Employment Income

For self-employed parents, income is gross business receipts minus ordinary and reasonable expenses. The word “reasonable” matters. Tennessee courts routinely add back excessive car expenses, inflated travel and entertainment, home office deductions, and accelerated depreciation.³

Because the schedule already accounts for the employee’s share of FICA (6.2%) and Medicare (1.45%), a self-employed parent paying the full 15.3% deducts the employer-equivalent portion from gross income before the calculation runs.³

Imputed Income

If a parent is voluntarily unemployed or underemployed, the court can assign them an income figure based on what they could reasonably earn. Tennessee looks at work history, education and training, ability to work, and lifestyle. A parent living in an expensive home while reporting minimal income draws scrutiny. The guidelines also weigh whether a stay-at-home parent held that role during the intact family, how long they’ve been out of the workforce, and the children’s ages.²

Incarceration is not treated as voluntary unemployment, and neither is active-duty service by a Reserve or National Guard member who was called up.

Costs Added to the Base Amount

The schedule amount does not cover everything. Three categories of expense are added on top and split by each parent’s income percentage:

Health insurance premiums for the child, including medical, dental, and vision.
Work-related childcare, such as daycare or after-school care needed so a parent can work.
Recurring uninsured medical costs, including co-pays, prescriptions, and therapy.

If you earn 55% of combined income and pay $400 monthly for the child’s health insurance, the other parent’s proportional share is factored into the final calculation.⁴

Private school tuition, special needs education, lab fees, and books are not automatic add-ons. They can be included, but only through a deviation from the presumptive amount.⁵

How Parenting Time Changes the Number

The guidelines assume the alternate residential parent has the children about 80 days a year, roughly every other weekend plus two weeks in summer and two weeks of holidays. Anything meaningfully different from that baseline moves the number.

At 92 or more days per year, the alternate residential parent gets a credit that reduces their obligation. The credit uses a variable multiplier tied to the number of days and the base support amount, and it grows as parenting time grows.² At 68 days or fewer, the obligation goes up, on the theory that the custodial parent is absorbing more direct costs.⁶

Sample Numbers From the Schedule

At $2,000 in combined adjusted gross monthly income, the base obligation is $421 for one child and $592 for two. At $5,000, it rises to about $893 for one child and $1,145 for two. For combined income above $28,250 per month, the base is $2,231 for one child plus 6.81% of income over that threshold, or $2,803 for two children plus 7.22% of the excess.

Remember, these are total obligations split between both parents by income percentage. The alternate residential parent’s share becomes the actual payment.

The Official Worksheet and Calculator

Tennessee requires parents to use the Child Support Worksheet published by the Department of Human Services. Using it is mandatory so every case runs on the same method. The worksheet walks through each step: gross income for both parents, adjustments, the base obligation from the schedule, additional expenses, and the parenting time adjustment.⁷

DHS offers downloadable Excel calculators for Windows and Mac, plus an iOS app in the Apple App Store. Download and save the file to your computer first. Filling it out in a browser will not produce accurate numbers.⁸

The Self-Support Reserve for Low-Income Payers

If the paying parent’s income is low, a self-support reserve keeps enough income in their hands for basic subsistence. The threshold is $957 in gross monthly income, set at 90% of the federal poverty level for one person. When the paying parent’s income falls within the shaded area of the schedule, the obligation is calculated using only that parent’s income and compared against the standard proportional result. The lower figure controls.¹

One trade-off: when the self-support reserve applies, the parenting time credit does not.

When a Court Can Deviate

The worksheet number is presumptively correct, but a court can adjust it in either direction. Any deviation requires written findings explaining why the guideline amount is unjust or inappropriate and how a different amount serves the child’s best interests.⁵

Common grounds include:

Extraordinary educational expenses, such as private school tuition or special needs schooling.
Special child-rearing expenses, such as summer camp, music or art lessons, extracurriculars, and travel.
Substantial travel costs when parents live far apart, weighed against which parent moved and why.
A child in the custody of the Department of Children’s Services, if reducing support helps a parent prepare for reunification.

No deviation is allowed if it would seriously impair the custodial parent’s ability to provide adequate housing, food, and clothing.⁵

Modifying an Existing Order

An order can be modified when there is a significant variance, defined as at least a 15% difference between the current obligation and what a new calculation would produce.⁹ Typical triggers are a substantial change in either parent’s income, a change in the child’s health insurance, additional children the paying parent becomes legally responsible for, or a change in parenting time. Run the current worksheet with updated numbers before filing a petition to confirm the 15% threshold is met.

1
Legal Information Institute. Tennessee Comp. R. and Regs. 1240-02-04-.03 – The Income Shares Model
2
Legal Information Institute. Tennessee Comp. R. and Regs. 1240-02-04-.04 – Determination of Child Support
3
Justia. Tennessee Rules and Regulations 1240-02-04-.04
4
Tennessee Department of Human Services. Child Support Guidelines – Frequently Asked Questions
5
Legal Information Institute. Tennessee Comp. R. and Regs. 1240-02-04-.07 – Deviations from the Child Support Guidelines
6
Tennessee Administrative Office of the Courts. Tennessee’s Income Shares Child Support Guidelines
7
Tennessee Department of Human Services. A Guide to Tennessee’s Child Support Worksheet
8
Tennessee Department of Human Services. Child Support Calculator
9
Legal Information Institute. Tennessee Comp. R. and Regs. 1240-02-04-.05