Use our calculator for Canadian spousal support estimates to help you understand what your support payments may look like. Use this free calculator to calculate spousal support according to the Canadian Spousal Support Advisory Guidelines, as well as child support (if applicable).You should keep in mind that this free online calculator only considers employment income and can only do simple calculations. Calculate Ontario spousal support in minutes. Generate a courtroom-ready report. There is a no precise formula for determining the amount that will be awarded for spousal support. There are two basic formulas used to calculate alimony in Ontario: the Without Child Support formula and the With Child Support formula. Please be sure to fill out the form upon registration to choose your child's gift package. The term of service begins at the conclusion of.