2019 NJ state tax due interest calculation math help

[SreenuPrabhaGMAl]

Hi, there is 2019 NJ state tax due $596 interest rate is prime 5.25% + 3% = 8.25% "compounded calculation" as per tb21(r) tax bulletin.

Q: How can we calculate interest for outstanding tax balance shown above?

Case 1: from 2020-May-17 to 2022-Jan-15 - how much interest $????  

Case 2: from 2020-May-17 to 2022-Apr-15 - how much interest $????

Tax bulletin: https://www.nj.gov/treasury/taxation/pdf/pubs/tb/tb21r.pdf  

Interest Rate Assessed on Tax Balances for 2019

The assessed interest rate on outstanding tax balances for the period January 1 – December 31, 2019, is 8.25%.
The rate is calculated as follows: Prime Rate (5.25%) + 3% = 8.25%, compounded annually. How this compounding works?
-->> interest assessed on outstanding tax balances is Prime Rate plus 3%.

appreciate help with mathematical calculations.  thank you.

[rjs]

Don't try to calculate the interest. Just pay what you owe and let the state bill you for the interest.

Compound interest is a standard financial computation method. You can find explanations of it with a web search. Here's one example.

Compound Interest

You can also find compound interest calculators on the web that will calculate the compound interest for you.