You should keep in mind that this free online calculator only considers employment income and can only do simple calculations. Use this free calculator to calculate spousal support according to the Canadian Spousal Support Advisory Guidelines, as well as child support (if applicable).To determine how much spousal support is required, calculate your gross income. This is the amount of money you make after taxes and other deductions. Use our calculator for Canadian spousal support estimates to help you understand what your support payments may look like. In Ontario, the laws surrounding spousal support are designed to ensure fairness and provide financial assistance where it's due. The with child support formula is actually a family of formulas, built around the custodial and child support arrangements for the children. Many people also refer to spousal support in Ontario as maintenance or alimony. You can either pay this amount in a lump sum or every month. Calculate Ontario spousal support in minutes.