Ok am I missing something easy or is this actually complicated?

I am trying to build a calculator specifically for financial planning for pilots. Pilots get a 16% non elective contribution to their 401(k)

Easy to calculate the future value of the 401(k) if I know principle, contributions, interest rate and amount of years to retirement.

It is not easy when the contributions will technically be different every year.

How do I show the FV when the contributions (salary*.16) will be adjusted every year say by 1.5?

Example: Year 1 >> Contribution = $220,000*.16=$35,200

Year 2 >> Contribution = [$220,000+($220,000*.015)]*.16
[$220,000+$3,300]*.16
$223,300*.16 = $35,728

As you can see, this makes the calculation of the FV a bit harder because the contribution is not consistent but it is consistently increasing.

IS THERE AN EASY WAY TO CALCULATE THIS?