An executor is entitled to whatever compensation is noted in the will under which they are serving. Most wills are silent on this point or simply state that the compensation shall be whatever the statutory commissions are.
New Jersey law sets base compensation according to the gross value of the estate as follows:
5.0% on the first $200,000
3.5% on the next $800,000
2.0% on anything above $1,000,000
So, for example, a New Jersey estate valued at $150,000 would yield $7,500 in executor fees ($150,000 x .05) and one valued at $1,200,000 would generate $42,000 in executor fees ($200,000 x .05 PLUS $800,000 x .035 PLUS $200,000 x .02). Note that assets with named beneficiaries (such as an IRA) are not normally included in the above calculations, since they are not considered to be part of the probate estate and pass directly to the beneficiaries. The relevant statute (N.J.S.A. 3B:18-14) can be found here.
The above is what is known as the corpus commissions. An executor is also entitled to a 6% commission on the income earned by the estate. Portions of income required to be withheld for tax purposes should still be included in this calculation. The relevant statute (N.J.S.A. 3B:18-24) can be found here
Finally, an executor always has the right to petition the court to allow additional compensation for "extraordinary" services. Such services might include things like facilitating the sale or lease of real estate, operating a business, managing litigation, navigating tax audits, and the like.
Under New Jersey law, multiple executors may be appointed in which case the total compensation is increased by 1% of the gross value of the estate per additional executor. Of course, in calculating the total compensation among all the executors, no one executor may receive a commission greater than the amount to which a single executor would be entitled.