Spousal Support Lab

Canadian courts and lawyers use the Spousal Support Advisory Guidelines (SSAG), published by the Department of Justice Canada. There are two formulas: the without-child-support formula (1.5% to 2% of the gross income difference for each year of cohabitation) and the with-child-support formula (40% to 46% of the difference in each spouse's Individual Net Disposable Income after child support, taxes and benefits). The SSAG produce a range, not a single number, and entitlement must be established before any formula is applied. This calculator runs both formulas so you can see the advisory range.

Under the without-child-support formula, annual spousal support ranges from 1.5% to 2% of the difference between the spouses' gross incomes, multiplied by each year of cohabitation (including pre-marriage cohabitation). The maximum is reached at 25 years together: 37.5% to 50% of the income difference. The high end is limited by an equalization-of-net-income cap so the recipient does not end up with more than about 50% of the couple's combined net income. For example, an $80,000 income difference over 10 years gives $12,000 to $16,000 per year.

When child support is also payable, the SSAG use a different machine: each spouse's Individual Net Disposable Income (INDI) is computed first — net income after taxes, CPP and EI, minus child support paid (payor) or plus child support received (recipient) — and spousal support ranges from 40% to 46% of the INDI difference. Child support always takes priority and is calculated first. Because INDI depends on taxes and benefits, this calculator includes a Canadian tax engine (federal + Ontario, BC or Alberta 2025 brackets) to approximate net income; professional software such as DivorceMate does the exact tax calculation.

The Rule of 65 is an SSAG duration trigger: if the marriage lasted 5 years or longer and the recipient's age at separation plus the years of cohabitation totals 65 or more, spousal support becomes indefinite (duration not specified). Example: a 50-year-old recipient separating after 15 years together hits 50 + 15 = 65, so support is indefinite. Support is also indefinite when the marriage itself lasted 20 years or longer. Otherwise duration is 0.5 to 1 year of support per year of cohabitation — the duration tab of this calculator checks both triggers.

Generally 0.5 to 1 year of support for each year of cohabitation — so 10 years together means 5 to 10 years of support. Support becomes indefinite (no end date set) if the marriage lasted 20 years or longer, or under the Rule of 65 (recipient's age at separation + years together >= 65, with at least 5 years together). With children, duration may instead be tied to milestones such as the youngest child starting full-time school or finishing high school, with a crossover to the without-child formula when child support ends.

A buyout converts periodic payments into one lump sum using present value: PV = annual payment x [1 - (1 + discount rate)^-years] / discount rate. The discount rate reflects the time value of money (money today is worth more than money later). For example, $15,000 per year for 10 years discounted at 3% has a present value of about $127,953 — not $150,000. The buyout tab of this calculator computes present value with an adjustable discount rate and optional annual payment growth (e.g. cost-of-living adjustments), and can also work backwards from a lump sum to the equivalent annual payment.

There is no single prescribed rate — it is negotiated or set by the court. Practitioners commonly use a risk-free or low-risk rate (often 2% to 5%), sometimes adjusted for inflation expectations. A higher discount rate shrinks the lump sum; a lower rate grows it. Because the rate dramatically changes the result, get professional advice before agreeing to a buyout, and use the calculator's rate slider to see how sensitive the lump sum is to the assumption.

Massachusetts is one of the few US states with a statutory-style formula: under the Alimony Reform Act of 2010, general-term alimony is generally 30% to 35% of the difference between the spouses' gross incomes, with a cap so that the recipient's total income (including alimony) does not exceed 40% of the couple's combined gross income. Duration is also capped: up to 50% of the marriage length in months for marriages of 5 years or less, rising to 80% for 15-20 year marriages, and indefinite at a judge's discretion beyond 20 years. Judges can still deviate, so treat this as a rough estimator.

Texas is restrictive: court-ordered spousal maintenance requires narrow eligibility (e.g. a 10+ year marriage with insufficient earning ability, family violence, or disability). When ordered, the amount is capped at the lesser of $5,000 per month or 20% of the paying spouse's average gross monthly income, and duration is capped at 5 years (10-20 year marriage), 7 years (20-30 years), or 10 years (30+ years). Texas courts presume maintenance is not warranted, so most Texas 'alimony' is actually contractual alimony negotiated privately, which has no caps.

Ontario uses the same federal SSAG as the rest of Canada — the formulas do not differ by province. What is Ontario-specific is property division: Ontario's Family Law Act uses net family property (NFP) equalization, where each spouse's NFP (assets minus debts at separation, minus assets minus debts at marriage, minus excluded property such as inheritances) is compared, and the spouse with the higher NFP pays the other half the difference. This calculator's property tab runs the full Ontario NFP equalization formula, including the matrimonial-home special rule.

In community-property states (California, Texas, Arizona, Nevada, Washington, Idaho, New Mexico, Louisiana and Wisconsin), assets and debts acquired during the marriage are generally split 50/50, while separate property (owned before marriage, or received as a gift or inheritance) stays with its owner. This calculator's property tab models that split: enter community assets, community debts and each spouse's separate property to see each side's share. Tracing and characterization disputes are common, so the result is a starting estimate, not a court outcome.

Australia has no fixed percentage formula: the Family Law Act uses a four-step process — (1) identify the net asset pool, (2) assess each party's financial and non-financial contributions (including homemaking and parenting), (3) consider future needs factors such as age, health, income capacity and care of children, and (4) check the overall result is just and equitable. Because steps 2-4 are discretionary, no calculator can produce a binding number; this tool's Australia section walks through the four steps as a structured overview so you can organize your own position before seeing a lawyer.

In Canada, periodic spousal support is generally tax-deductible for the payor and taxable income for the recipient, while a lump-sum payment is generally neither deductible nor taxable — which is one reason buyout math matters. In the US, for divorce agreements executed after December 31, 2018 (Tax Cuts and Jobs Act), alimony is no longer deductible by the payor nor taxable to the recipient at the federal level; pre-2019 agreements generally keep the old treatment. Tax rules affect INDI and settlement negotiations, so confirm the current rules with a tax professional in your jurisdiction.

Retirement is one of the most common reasons support is reviewed or varied, but it does not automatically end it. Under the SSAG, retirement may justify reducing or terminating support depending on the recipient's needs, the payor's post-retirement income, and whether the original order anticipated retirement. Indefinite support (20+ year marriages or Rule of 65) is most likely to be revisited at retirement. If you are modeling support through retirement, use the buyout tab to compare a lump sum against payments that stop at a planned retirement date.

No. This tool is an educational estimator only. The SSAG are advisory guidelines that produce ranges, and entitlement to support must be legally established before any formula applies; courts can and do depart from the ranges. US alimony outside a few states is largely discretionary. Property division involves tracing, valuation and judicial discretion that no calculator can replicate. Always consult a licensed family-law lawyer in your jurisdiction before making decisions or signing anything.

Yes. This tool is 100% client-side: every calculation happens in your browser and no data is sent to any server. There are no accounts, no sign-ups and no tracking of the numbers you enter. It keeps working offline after the first load — just bookmark it.