Beginner guide
This guide explains what the GST Return Calculator does, what numbers you need, and how to read the final result before preparing your GSTR-3B filing.
The GST Return Calculator gives an approximate monthly GST payable figure for GSTR-3B planning. It combines taxable sales, GST rate, reverse charge, input tax credit, interest, and late fee into one simple summary.
It does not file your return and it does not replace reconciliation. Think of it as a working estimate before you check your books and GST portal data.
Outward taxable supplies are your taxable sales for the period. Enter sales within your own state as intra-state taxable value. Enter sales to another state as inter-state taxable value.
The calculator treats intra-state tax as CGST plus SGST, and inter-state tax as IGST.
Select the average GST rate for the taxable sales you entered. If all your sales are at 18%, choose 18%. If your sales use multiple rates, either calculate each category separately or use a weighted average for a quick estimate.
Nil or exempt supplies are reported for visibility but usually do not create tax payable. Reverse charge mechanism, or RCM, applies when you must pay GST directly on certain purchases or services.
Input tax credit is the GST credit available from eligible purchases. Enter your IGST, CGST, and SGST credit from your books or portal data. The calculator subtracts matching ITC from the output tax heads to estimate the balance payable.
Estimated cash payable is the approximate amount due after reducing available ITC from output tax, and adding RCM, interest, or late fee. Use it to plan cash flow before final filing.