Free Spousal Support Calculator

Spousal support in British Columbia is calculated using the Spousal Support Advisory Guidelines (SSAG). Unlike child support, the SSAG are advisory, not legally binding — but BC courts and family lawyers treat them as the default starting point in almost every case.

The Guidelines produce a range (low, mid, high) for the monthly amount and a separate range for duration. Where you land in that range depends on entitlement, need, compensatory claims, and the overall financial picture of each party.

The SSAG has two separate formulas, and choosing the right one is the first step of any calculation:

• Without-child-support formula. Applies when there are no dependent children, or when child support is not being paid. The math is based purely on the gross income difference between the spouses and the length of the relationship: the monthly amount is 1.5% to 2% of the income difference per year of cohabitation, capped at 50% of the gap. This is the formula for long marriages without minor children, empty-nest separations, and shorter childless relationships.
• With-child-support formula. Applies when child support is also being paid for a dependent child of the relationship. Instead of working with gross income, this formula works with net disposable incomeafter taxes and child support, and targets a specific share of combined net disposable income for the recipient. It's more complex — and far more sensitive to the specifics of the tax credits and benefits each party receives.

You don't need a separate tool for the child support figure — this calculator computes it internally using the Federal Child Support Guidelines, then feeds that number into the with-child SSAG formula. If you'd prefer to see the pure child support number on its own, the BC Child Support Calculator is the dedicated view.

Both SSAG formulas produce a range rather than a single number. The purpose of the range is to leave room for judicial discretion and negotiation.

Most BC negotiated settlements land somewhere near the middle — but lawyers routinely argue for the low or high end based on the specific facts.

The SSAG give a duration range as well as a monthly range. Under the without-child formula, duration is roughly 0.5 to 1 year of support per year of cohabitation. A 10-year relationship typically produces a 5-to-10-year support range. Two doctrines extend duration:

• The rule of 65. If the recipient's age plus the length of the relationship equals 65 or more at separation, support is typically indefinite(meaning of unspecified duration, subject to review — not necessarily “forever”).
• Merger over time. The longer a relationship lasts, the more the spouses' economic lives merge. Relationships of 20 years or longer automatically produce indefinite support, regardless of age.

The with-child formula uses two separate duration tests — the length-of-marriage test (like the without-child formula) and a “longer of” rule tied to the youngest child's schooling. Whichever produces a longer duration wins.

The SSAG only tell you how much and how long — they assume entitlement has already been established. In Canadian family law, entitlement to spousal support comes from one of three sources:

• Compensatory. The recipient suffered an economic disadvantage from the relationship or its breakdown — typically because they took on the bulk of child-rearing or gave up career progression to support the other spouse's career.
• Non-compensatory (needs-based). The recipient simply cannot meet their reasonable needs after separation, and the other spouse has the ability to help. This often applies in long relationships where lifestyles have converged.
• Contractual. The parties have a written agreement (marriage agreement, cohabitation agreement, or separation agreement) that provides for support.

This calculator is fully transparent — here's exactly what it does:

• Formula selection. If you indicate dependent children and child support is in play, the with-child formula runs. Otherwise the without-child formula runs.
• Tax engine. For the with-child formula, the calculator computes net disposable income using the 2026 federal and BC income tax brackets, CPP and EI contributions, basic personal amounts, the Canada Employment Amount, and the main refundable credits (Canada Child Benefit, GST credit, BC Family Benefit).
• Convergence loop. The with-child formula is self-referential — spousal support affects taxes, which affect net disposable income, which affects the support amount. The calculator solves this with an iterative convergence loop that stops once the numbers stabilize within one dollar.
• Imputed income. If you enter imputed income for either party, the calculator treats it exactly as a court would: as though it were actual earned income, flowing through the tax engine and the Guidelines.
• No data leaves your browser. Everything runs client-side.

The tax engine and SSAG implementation are open source under Apache-2.0. The calculator on this page is powered by OpenSSAG.