Using calculations by Nick Kasprak from the Center on Budget and Policy Priorities and Kyle Pomerleau from Tax Foundation, Amanda Cox shows tax penalties and bonuses for married couples.
The x-axis is total earnings, and the y-axis is the split between the couples. Percentages for penalties and bonuses are versus what couples would pay if they were allowed to file individually. Make your way towards the low end or high end of total earnings, closer to a 50-50 split between the pair, and you run into higher penalties.
Have a child? It gets more painful almost all across the board.
Enter your salary and your spouse’s salary to see where you are. Good times.