People who discount the value of a 401k do not have a Calculator or clearly do not know how to use it & what numbers to input?

First you need to become familiar with the rules relating specifically to 401k

Then you must understand all aspects of Income Tax for Employees & Employers

Examine the differentials between each type of tax and work through an example of a moderate to high income earner – choose $80,000 to make the mental arithmetic easy

Consider the impact on all of variations in outcome when: Personal Contributions are made by Workers

When Employers make matching contributions

When they do not

When Employees make a salary sacrifice

When Employers match the Salary Sacrifice with a contribution

What is the effect of borrowing 50% of the Total Fund Contributions

What is the impact when:Workers Borrow the money to make a 401k Contribution

Employers Borrow the money to make a matching 401k Contribution of workers

Where Workers invest the money obtained when they Borrow the money from their 401k Fund

Calculate the Tax Effect when workers contribute to a 401k – with their own money and when they use borrowed money

What is the ROI in each case

What is the ROI for an Employer making a matching contribution when the Employee makes a salary sacrifice:

And when the Employer also borrows the full amount of their matching contribution (when they have received a salary sacrifice by their Employee)?

Examine the position of a worker once their Employer has matched their Personal Contribution to a 401k Plan?

What are the financial gains at each stage: i) On making their own Max contribution:

Assume A Salary Sacrifice: ii) When their Employer Matches their contribution

What does it cost an Employee to make a Maximum Personal Contribution to their 401k Plan?

Look at the Dollar amounts and ROI –

apply a borrowing cost of 5%

Make a comparison when a zero interest loan is available for the initial 15 months

How might using a loan from their 401k suit end of term when the Zero cost loan has to be refinanced?

Eyes glaze over when residents are in States which have taxes.

The financial benefits can be larger in those states – provided effort has been put in to structuring the right 401k plan.

Not much point throwing numbers at you until you have a complete grasp of all the variables and parameters – which have a lot turns on the road.