The Kaiser Family Foundation has a subsidy calculator that also translates your family income into a percentage of Federal Poverty Limit, which can be useful in determining which subsidies and rules may apply to you.
An even more useful tool is from Value Penguin (don’t let the name fool you, it is very sophisticated), which shows you the premiums and basic terms of the various Obamacare insurance plans that you may be able to enroll in given you income, family size, and geographic location.
Here is a chart of CHIP eligibility for Pennsylvania broken down by family size and income bracket. It includes premiums and copay levels.
Here is a chart of Federal Poverty Level guidelines for various family sizes.