A trade-in larger than the price

Taxable amount cannot go below zero. The extra trade-in still reduces the loan like cash.

Tax stops at zero

Price minus trade-in, when negative, is treated as zero for tax. You are not given a negative tax credit in the loan.

The loan formula still subtracts the full trade-in. A trade-in bigger than the price can wipe out the loan and more, down to a zero loan. It does not create a cash refund on this screen.

Check the dealer worksheet

Some deals cut a check for the unused equity, or apply it to fees that are not in this form. If they cut a check, the calculator will not show that cash. Your loan should still be typed to match what you finance, which may be zero.

If they apply the equity to a different product, do not also count it as trade-in and as a lower price.

Ownership remains

A zero loan with a full insurance and fuel estimate is a paid-for car in the month. That can be the right picture.

The offer comparison has nothing to compare if the principal is zero. Payments are zero on both sides.

This explains how WiseCalculator treats the numbers you type. It is not a lender’s offer and it is not advice for your loan.