Marks Calc

Calculate GST, Sales Tax & Reverse Tax Instantly

Free tax calculator for Indian GST rates (5%, 12%, 18%, 28%). Add tax to any amount or extract tax from a tax-inclusive price. Shows pre-tax amount, tax amount, and total.

How It Works

Tax = Price × (Rate/100); Inclusive: Pre-tax = Price / (1 + Rate/100)

For tax-exclusive amounts, multiply by the tax rate percentage to get the tax. For tax-inclusive amounts, divide by (1 + tax rate) to extract the pre-tax price. The difference is the tax amount.

Quick Tips

GST Rates
India has 4 GST slabs: 5% (essentials), 12% (processed food), 18% (most goods/services), 28% (luxury items, sin goods).
Reverse Tax
If a MRP includes tax, toggle "Tax Included in Price" to extract the base price and tax amount separately.
GSTIN
Every registered business has a 15-digit GSTIN. Verify it on the GST portal before claiming input tax credit.
Composition Scheme
Small businesses (turnover < ₹1.5 crore) can opt for composition scheme with lower rates: 1-6% instead of regular GST.

Step-by-Step Instructions

  1. 1Enter the amount (price of goods or services).
  2. 2Set the tax rate (use Indian GST presets or enter custom rate).
  3. 3Toggle whether the amount includes or excludes tax.
  4. 4View the pre-tax price, tax amount, and total price instantly.

Frequently Asked Questions

What is the GST rate in India?
India has 4 main GST slabs: 5% (essential items like food grains), 12% (processed foods, fabrics), 18% (most goods and services like electronics, restaurants), and 28% (luxury cars, tobacco, aerated drinks).
How do I calculate tax from a total that includes tax?
Toggle "Tax Included in Price" and enter the total amount. The calculator will extract the base price and tax amount. For example, ₹118 inclusive at 18% GST = ₹100 base + ₹18 tax.
What is the difference between CGST and SGST?
For intra-state sales, GST is split equally: CGST (central) + SGST (state). For inter-state sales, IGST goes entirely to the center. The total rate remains the same.
Is MRP inclusive of GST?
Yes. By law, MRP (Maximum Retail Price) must be inclusive of all taxes including GST. You can use the reverse tax mode to find the pre-tax price from MRP.