GST CMP-08 Calculator
Work out your quarterly composition tax live — turnover × flat rate, split into CGST & SGST, plus any reverse-charge tax, all on one screen.
- Free — no sign-up
- Instant, on-screen results
- Built by our CA · CS team
- Rules cited on the page
Enter your figures — the result on the right updates as you type.
CMP-08 payment breakdown
Let a CA file your CMP-08 & GSTR-4
Quarterly statement-cum-challan filed on time, plus your annual return — no penalties, no missed dates.
Disclaimer: Indicative estimate for GST composition dealers under Section 10. RCM tax uses a flat 18% assumption; your actual reverse-charge rate depends on the specific supply. Verify with your CA before filing.
What is CMP-08?
CMP-08 is the quarterly statement-cum-challan through which a GST composition dealer pays tax. Instead of charging GST on invoices and claiming input credit, a composition taxpayer pays a small flat percentage of turnover and files one simple challan each quarter, plus an annual return in GSTR-4.
Composition tax rates
The flat rate depends on the nature of your business. It is always split equally between CGST and SGST, and is paid on the turnover of taxable supplies for the quarter.
| Trader (goods) | 1% (0.5% + 0.5%) |
| Manufacturer | 1% (0.5% + 0.5%) |
| Restaurant (non-alcohol) | 5% (2.5% + 2.5%) |
| Service supplier u/s 10(2A) | 6% (3% + 3%) |
| Trader / Manufacturer | 0.5% + 0.5% |
| Restaurant | 2.5% + 2.5% |
| Service supplier | 3% + 3% |
| Reverse charge (RCM) | Normal rate (18%) |
How CMP-08 tax is calculated
Composition tax = quarterly turnover × flat rate. Split it equally into CGST and SGST, then add any tax payable under reverse charge. Here are three examples on ₹15,00,000 of quarterly turnover with no RCM:
Key terms explained
Composition scheme
A simplified GST route under Section 10 for small taxpayers. You pay a flat percentage of turnover instead of regular GST, with far less compliance — but you give up input tax credit.
Reverse charge (RCM)
On certain inward supplies the buyer pays GST instead of the seller. A composition dealer must pay this at the normal rate, over and above the flat composition tax, and cannot claim it as credit.
No tax collection
A composition dealer cannot collect GST from customers or issue a tax invoice — only a bill of supply. The composition tax comes out of your own margin.
GSTR-4 annual return
Besides the quarterly CMP-08 challan, composition taxpayers file GSTR-4 once a year to report the full year's turnover and tax. Both filings are mandatory to stay compliant.
Questions people ask
Short answers on GST CMP-08 Calculator. Tap a question to open it.
01What is CMP-08?
The quarterly statement through which a composition taxpayer declares the tax payable for the quarter and pays it. It replaced the earlier quarterly return and is a summary statement, not a detailed return.
02When is CMP-08 due?
By the 18th of the month following each quarter. The annual return in GSTR-4 follows by 30 June after the financial year ends.
03What rate applies under composition?
1% of turnover for traders and manufacturers (0.5% CGST plus 0.5% SGST), 5% for restaurant services not serving alcohol, and 6% for the composition scheme available to small service providers.
04Is reverse charge tax included in CMP-08?
Yes. A composition taxpayer must pay tax under reverse charge at the normal rate on notified inward supplies, and that is declared and paid in CMP-08 in addition to the composition levy.
05What is the late fee for CMP-08?
The standard daily late fee applies for filing after the due date, plus interest at 18% per annum on the tax paid late. A nil statement still has to be filed on time.
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Disclaimer: This tool gives indicative results for general guidance only and is not professional advice. Please verify with a qualified CA before acting on the numbers.