There's no formula for deciding a property settlement, but if you can reach agreement with the other party, then it can be whatever you like.
If not, though, the court follows a four-step process for determine a property settlement:
1. What is the total value of the joint asset pool?
2. What were the financial and non-financial contributions of each party?
3. What are the future needs of each party?
4. Is the settlement just and equitable?
Most separating parties find it helpful to start at 50/50 and then make adjustments as necessary. For example, if you both worked but the other party contributed significantly more to the mortgage, then it would perhaps swing 5% in his favour. However, if you have care of the kids moving forward, then that's a future need and it might swing back another 5% in your favour.
Hope this helps.
