What is the upper limit for federal estate tax exemption?

The 2015 estate tax limit is $5.43 million per person, according to Forbes. This limit represents a $90,000 increase in the allowable estate value from the 2014 limit of $5.34 million. Estates over the $5.43 million limit are liable for the top federal estate tax rate of 40 percent.

The federal estate tax is a tax imposed on the transfer of property from a deceased individual to his heirs, explains the Center on Budget and Policy Priorities. As of 2015, only 2 out of ever 1,000 deceased individuals leave behind an estate of high enough value to exceed the estate tax exemption. As of 2013, individuals liable for estate taxes paid an average of 16.6 percent of their inherited estate's value.