Business guides

Business guides for owners and finance teams

Short, practical explainers on the questions our calculators get used for — the formula, a worked example, and the tool that does it for you.

GST & tax

How to calculate GST

Multiply the taxable value by the GST rate to add tax; divide the inclusive price by 1 + rate/100 to remove it.

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GST 2.0: the new GST rates explained

From 22 September 2025, GST runs on four slabs (0%, 5%, 18% and a 40% special rate) with most 12% items moving to 5% and most 28% items moving to 18%.

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CGST vs SGST vs IGST

Same-state sale: GST splits equally into CGST and SGST. Different-state sale: the whole rate goes on one IGST line.

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How to create a GST invoice

A tax invoice needs your GSTIN, a consecutive number, the customer details, HSN/SAC, taxable value and the GST split.

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Pricing & profit

How to calculate profit margin

Margin % = (Selling price − Cost) ÷ Selling price × 100. Always measured against revenue, not cost.

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Markup vs margin

Markup is calculated on cost; margin on the selling price. The same rupee profit gives two different percentages.

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Finance

How to calculate EMI

EMI = P × r × (1+r)^n ÷ ((1+r)^n − 1), where r is the monthly rate and n the number of months.

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Salary & HR

CTC vs take-home salary

CTC includes employer PF, gratuity and benefits. Take-home is gross pay minus PF, professional tax and TDS.

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Billing & Invoicing

What to include on an invoice

Business and customer details, an invoice number, dates, line items, tax and a total due: everything else is optional but useful.

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Quote vs invoice

A quote is sent before work starts and has a valid-until date. An invoice is sent for payment and has a due date.

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Prefer to skip the maths?

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