GST Payment Calculator
Simple & Fast | Smart CGST–SGST Sync | Net Payable or Carry Forward per Head
A Free Tool by B.A. Bedawala & Co., Chartered Accountants
For Regular GST-registered dealers (Monthly GSTR-3B). Applies ITC utilization rules under Section 49A/49B + Rule 88A of CGST Rules.
Smart sync: Typing in CGST auto-fills SGST (and vice versa). You can override if needed.
1. Return Period
2. GST Payment Computation ?
| Particulars | IGST | CGST | SGST |
|---|---|---|---|
| Output GST Liability Tax on outward supplies (excl. RCM) | |||
| RCM Liability Reverse charge — paid in cash only | |||
| Opening ITC Balance Credit b/f from previous period | |||
| ITC for the Month Eligible ITC as per GSTR-2B (excl. this month's RCM) |
CGST auto-fills SGST (and vice-versa) for convenience. Once you manually edit a field, it stays independent so you can enter different values.
⚠️ RCM is paid in cash. ITC cannot discharge RCM liability. RCM tax paid is itself eligible as ITC in the same period (subject to Section 16) — if claiming it now, add those amounts into the "ITC for the Month" row.
Note: "Opening ITC" and "ITC for the Month" are added together as total available credit. ITC is utilised against output tax only (not RCM), per Rule 88A & Circular 98/17/2019 for minimum cash outflow.
❓ Frequently Asked Questions
What is the order of ITC utilization under GST?
As per Rule 88A read with Sections 49A & 49B of the CGST Act: (1) IGST ITC must first be fully utilized against IGST liability. (2) Remaining IGST ITC can then be applied to CGST or SGST liability in any order/proportion. (3) CGST and SGST credits can only be used for their own heads or for IGST — they cannot cross-utilize (CGST ITC cannot pay SGST and vice versa).
How is interest calculated under Section 50(1)?
Interest @ 18% per annum is charged on the net cash liability (amount paid through Electronic Cash Ledger) when GSTR-3B is filed after the due date. As per Rule 88B (inserted by Notification 14/2022), interest is calculated from the day after due date till the date of actual debit to cash ledger. No interest on ITC-utilized portion.
Why is RCM paid in cash even when I have ITC?
As per Section 49(4) of the CGST Act, the Electronic Credit Ledger (ITC) can only be used to pay output tax liability — not tax payable under Reverse Charge Mechanism. RCM must be discharged through the Electronic Cash Ledger. However, the RCM tax paid becomes ITC eligible in the same month itself (subject to Section 16 conditions).
Can CGST ITC be used to pay SGST liability?
No. As per Section 49(5) of CGST Act, CGST ITC cannot be used for SGST/UTGST liability and vice versa. They can only be cross-utilized against IGST liability after own-head liability is settled. This preserves revenue bifurcation between the Centre and the respective State.
What happens to unused ITC at the end of the month?
Any ITC not utilized in a tax period is carried forward to the next tax period in the Electronic Credit Ledger. ITC does not expire at the end of the financial year, but must be availed within the time limit prescribed under Section 16(4) — by 30th November of the following FY or filing of annual return, whichever is earlier.
Why do CGST and SGST auto-sync in this calculator?
Under GST, intra-state supplies attract equal CGST and SGST (half of total GST rate each). For example, 18% GST on intrastate sale = 9% CGST + 9% SGST. For convenience, entering one auto-fills the other. However, the moment you manually edit either field, it becomes independent and will not be overwritten — so you can enter different CGST and SGST figures where required (e.g., post-reconciliation adjustments, prior-period corrections, or different rounding).
What is the time limit for availing ITC?
As per Section 16(4), ITC on any invoice for a financial year must be availed by the 30th of November of the following financial year, OR before furnishing the relevant annual return, whichever is earlier. Beyond this, ITC lapses.
When is GSTR-3B due?
For monthly filers, GSTR-3B is due on the 20th of the following month. Example: March 2026 return due on 20-April-2026. Taxpayers under QRMP scheme file quarterly but pay tax monthly via PMT-06 by 25th. Late filing attracts interest u/s 50 plus late fee u/s 47.