To calculate gross income:

1. Determine the tax rate.
2. Subtract any deductions from the net amount.
3. Divide by the after-tax percentage.

Here's an example:
Let's say your net income is and the tax rate is 20%. You also have a retirement contribution of .
1. Subtract the retirement contribution from the net income: $50,000 - $5,000 = $45,000.
2. Divide by the after-tax percentage: $45,000 / 0.8 = $56,250.

To calculate net income:
Subtract any taxes and deductions from the gross amount.

To adjust your budget:
1. Determine the tax rate and any deductions.
2. Divide the net amount by the after-tax percentage to calculate the gross amount of the adjustment.
3. Subtract the taxes to determine the net amount.

Here's an example:
Let's say you need to adjust your budget by . The tax rate is 25% and there are no other deductions.
1. Divide the net amount by the after-tax percentage: $1,000 / 0.75 = $1,333.33.
2. Subtract the taxes: $1,333.33 * 0.25 = $333.33.
3. Determine the net amount: $1,000 - $333.33 = $666.67.