How to Calculate Tax and Income –
Simple Explanation with Examples
Many taxpayers get confused about how to calculate tax when they already have an amount, and how to find actual income when tax is included in the total amount.
This article explains both situations step by step, using simple formulas and examples.
1. When You Have the Amount and Want to Calculate Tax
Situation
You know the income amount, and tax is not included yet.
Formula
Tax = Amount × Tax Rate ÷ 100
Example
Amount = 100,000
Tax Rate = 15%
Calculation:
100,000 × 15 ÷ 100 = 15,000
Result
-
Income: 100,000
-
Tax: 15,000
-
Total payable (if tax is extra): 115,000
When to Use This Method
Use this formula when tax is added separately to income.
2. When You Have the Total Amount and Tax Is Already Included
Situation
You already have the final amount, and this amount includes tax.
Important Concept
The total amount is not 100% income.
It is income + tax, which means:
Total = 100% income + 15% tax = 115%
That is why we divide by 115, not 100.
Formula
Income = Total Amount ÷ (100 + Tax Rate) × 100
Tax = Total Amount × Tax Rate ÷ (100 + Tax Rate)
Example
Total Amount = 100,000
Tax Rate = 15%
Tax Calculation:
100,000 × 15 ÷ 115 = 13,043
Income Calculation:
100,000 − 13,043 = 86,957
Result
-
Total Amount: 100,000
-
Tax Included: 13,043
-
Actual Income: 86,957
Why Is Tax Less Than 15,000?
Because 15% is calculated on actual income, not on the final amount.
When tax is included, the base income becomes smaller.
Quick Comparison Table
| Situation | Formula Used |
|---|---|
| Tax is extra | Amount × Rate ÷ 100 |
| Tax is included | Amount × Rate ÷ (100 + Rate) |
Final Rule to Remember
-
If tax is not included, divide by 100
-
If tax is included, divide by (100 + tax rate)
Conclusion
Understanding the difference between tax-exclusive and tax-inclusive amounts helps avoid calculation mistakes and ensures correct tax filing.
For more simple tax guides, visit TaxationWithAtif regularly.
