Margin: What It Means in Finance & How to Calculate It

Updated 12 Mar 2026Content was accurate at the time of publication

What is margin?

Margin has two related but distinct meanings in finance. First, margin as a profitability metric measures how much of each dollar of revenue remains after costs — think gross margin, operating margin and net margin. Second, margin in trading and lending refers to collateral or borrowed funds used to increase position size: a margin account lets you borrow to invest, subject to initial and maintenance margin rules and potential margin calls. Whether you're deciding whether to use leverage or trying to understand your business profitability, these practical definitions, calculations and checklists will help you make informed decisions.

Common types of margin

Gross margin — revenue minus cost of goods sold (COGS), expressed as a percentage of revenue.
Operating margin — operating profit (EBIT) divided by revenue.
Net margin — profit after tax divided by revenue.
Contribution margin — revenue minus variable costs per unit; useful for pricing and volume decisions.
Initial margin — upfront collateral required to open a leveraged position.
Maintenance margin — minimum equity percentage you must keep; falling below it can trigger a margin call.
Margin lending — borrowing from a broker to buy securities; includes margin account mechanics and margin interest.

See also related concepts in profitability analysis and investing.

Profit margins: formulas and examples

Key formulas

Gross margin (%) (Revenue − COGS) / Revenue × 100
Operating margin (%) Operating profit / Revenue × 100
Net margin (%) Net profit / Revenue × 100

Worked example 1: single product sale

You sell a widget for $150. The cost to make it (COGS) is $10.

Revenue = $150; COGS = $10
Gross margin = (150 − 90) / 150 × 100 = 60 / 150 × 100 = 40%

That 40% means $1.40 of every $1.00 revenue remains to cover operating costs, interest and tax.

Worked example 2: small business P&L (quarter)

Revenue: $100,000
COGS: $120,000
Operating expenses (wages, rent, marketing): $10,000
Interest & tax: $10,000

Calculations:

Gross margin = (200,000 − 120,000) / 200,000 × 100 = 40%
Operating profit = 200,000 − 120,000 − 50,000 = $10,000 Operating margin = 30,000 / 200,000 × 100 = 15%
Net profit = 30,000 − 10,000 = $10,000 Net margin = 20,000 / 200,000 × 100 = 10%

These margins let you compare performance across periods, products, or peers.

Margin vs markup

People often confuse margin and markup. They're related but different:

Markup (%) is how much you add to cost to set price: Markup % = (Selling price − Cost) / Cost × 100
Margin (%) is the portion of the selling price that is gross profit: Margin % = (Selling price − Cost) / Selling price × 100

Conversion formulas:

From markup to margin: Margin = Markup / (1 + Markup) (use decimals)
From margin to markup: Markup = Margin / (1 − Margin)

Example: 20% markup means markup = 0.20 → margin = 0.20 / (1 + 0.20) = 0.1667 → 16.67% margin.

Margin in trading and lending

Basics

When you trade on margin you borrow from a broker to buy securities, using your existing holdings as collateral in a margin account. Margin lending increases potential returns but also amplifies losses.

Key terms:

Initial margin — percentage of the position you must fund yourself when opening.
Maintenance margin — minimum equity percentage required after the position is opened.
Margin call — broker demand for additional funds or sale of assets if equity falls below maintenance margin.

How broker requirements work

Brokers publish margin schedules. Example: you buy shares worth $10,000 with 50% initial margin. You provide $1,000 and borrow $1,000. If maintenance margin is 30%, your equity must stay ≥ 30% of market value.

Brokers may change margin requirements with market conditions; higher volatility often leads to higher required margins.

Margin call price: formula and example

To find the share price that triggers a margin call for a long position, use:

Price_call = Loan / (N × (1 − maintenance_margin))

Where Loan is the borrowed amount and N is the number of shares.

Worked example:

You buy 200 shares at $10 = $10,000 total.
You borrow $1,000 (initial equity $1,000). Maintenance margin = 25% (0.25).

Price_call = 4,000 / (200 × (1 − 0.25)) = 4,000 / (200 × 0.75) = 4,000 / 150 = $16.67

If the share price falls to approximately $16.67, your equity percentage hits the maintenance threshold and the broker may issue a margin call.

Costs & interest on margin borrowing

When you borrow to invest you pay margin interest and possibly fees. Margin rates are often quoted as a spread over the broker's base rate and move with market rates — the RBA cash rate influences bank funding costs, which in turn affects margin rates. See RBA cash rate history: https://www.rba.gov.au/statistics/cash-rate/

Simple interest example:

Borrow $10,000 on margin at 8% p.a. for one year → interest = $10,000 × 0.08 = $100.

If the investment return is 6% ($100) you incur a net loss of $100 after interest (ignoring fees and tax).

Check your broker's margin schedule before deciding to borrow.

Risks & risk management

Margin multiplies both gains and losses. Key risks include:

Leverage risk — small price moves can cause big equity swings.
Forced liquidation — brokers may sell positions without consent to meet margin calls.
Volatility — higher volatility increases the chance of margin calls.
Liquidity risk — selling thinly traded assets at low prices when forced.

Practical risk-management steps:

Maintain a buffer above your maintenance margin (e.g., target equity 1.2–1.5× required).
Use position sizing: limit any single margin position to a small share of your portfolio.
Set stop-loss orders but remember stops can gap in fast markets.
Diversify across uncorrelated assets to reduce forced-sale risk.
Monitor positions daily and stress-test scenarios (price drops of 10–30%).
Choose conservative initial/leverage ratios if you're inexperienced.

If you use margin for business asset purchases, compare alternatives like asset finance and business loans.

If you're using margin: quick checklist

Check broker's initial and maintenance margin schedule.
Know margin interest rate and fee structure.
Set alerts for equity% thresholds.
Keep emergency cash or low-risk collateral available.
Review tax implications with an adviser.

Regulatory & tax considerations

Regulators provide guidance and protections you should review:

MoneySmart — margin lending overview: https://moneysmart.gov.au/investing/borrowing-to-invest/margin-lending
ASIC — general investor guidance: https://asic.gov.au/
ASX — market and clearing rules: https://www.asx.com.au/
ATO Business — tax treatment and deductions: https://www.ato.gov.au/Business/
RBA cash rate and policy: https://www.rba.gov.au/

Interest on borrowed money may be deductible if funds are used to produce assessable income, but conditions apply. Always check the ATO guidance and consider professional tax advice.

Before using margin lending, review your broker's Product Disclosure Statement (PDS), margin schedule and ASIC/MoneySmart guidance.

Quick calculators and worked examples

Formulas you can paste into a spreadsheet:

Gross margin %: =(Revenue − COGS) / Revenue * 100
Net margin %: =NetProfit / Revenue * 100
Markup to margin (decimal): =Markup / (1 + Markup)
Margin call price (long): =Loan / (N * (1 − maintenance_margin))

Worked margin-call example recap (from earlier): 200 shares, $10 entry, $1,000 loan, 25% maintenance → call price ≈ $16.67.

If you want an interactive calculator, check your broker's margin calculator or internal tools.

FAQ

What is the difference between margin and markup?

Margin is profit as a share of selling price; markup is the increase over cost. See markup vs margin for examples.

How do I calculate gross margin?

Use (Revenue − COGS) / Revenue × 100.

What is a good profit margin for my business?

It depends by industry. Compare to peers and track trends; gross vs net margins tell different stories.

What is a margin call and how can I avoid one?

A margin call is a demand for funds when equity falls below maintenance margin. Avoid by using conservative leverage and keeping cash buffers.

How do initial and maintenance margin requirements differ?

Initial margin is required to open a position; maintenance margin is the ongoing minimum.

How is margin interest calculated?

Typically as simple interest on the borrowed balance at the broker's stated annual rate.

Can I deduct margin interest for tax purposes?

Interest may be deductible if the loan funded income-producing investments; check ATO rules and consult a tax adviser: https://www.ato.gov.au/.

What should I check before using margin lending from a broker?

Check PDS, margin rates, margin schedule, forced-sale policy, and ASIC/MoneySmart guidance.

How does volatility affect my margin requirements?

Higher volatility increases the risk of price moves and may lead brokers to increase margin requirements.

Where can I find my broker's margin schedule?

In its PDS or on its website; if unclear, ask the broker in writing.

Is margin the same as a loan?

Margin borrowing is a secured loan using your securities as collateral — it behaves like credit with interest and covenants.

Should I use margin for business growth or asset purchases?

For business assets consider alternatives like asset finance or business loans; compare rates and terms before deciding.

Key takeaways

Margin is both a profitability ratio and a borrowing mechanism. Use the formulas and examples above to measure business performance and the margin-call formula to stress-test leveraged positions. Carefully weigh margin interest, broker rules and regulatory guidance (ASIC/MoneySmart), and manage risk with conservative sizing, buffers and diversification. Always review your broker's margin schedule and consult a tax adviser about deductions before proceeding.