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Cost and Management Accounting · Marginal Costing

Cost-Volume-Profit Analysis and P/V Ratio

Updated 4 October 2026 · Fact-checked

CVP analysis studies how profit changes when sales volume, selling price and costs change. Contribution is sales minus variable cost. P/V ratio is contribution ÷ sales × 100. Margin of safety is actual sales minus break-even sales. Find the P/V ratio first, then use it to get profit, sales and safety margin.

Understand Cost-Volume-Profit Analysis and P/V Ratio

Every cost behaves in one of two ways. Variable cost changes with output. Fixed cost stays the same in total within the relevant range. CVP analysis uses this split to show how volume, price and cost together decide profit.

Contribution is sales minus variable cost. It is the amount each unit gives towards covering fixed cost. Once fixed cost is fully covered, the rest of the contribution becomes profit. So: Contribution = Fixed cost + Profit.

The P/V ratio (profit-volume ratio, also called contribution to sales ratio) expresses contribution as a percentage of sales. Because fixed cost does not change, any extra sales add to profit at the P/V ratio. A 10% P/V ratio means every extra ₹100 of sales adds ₹10 to profit.

The break-even point is the sales level where contribution equals fixed cost, so profit is nil. The margin of safety is how far actual or budgeted sales are above break-even. A large margin means sales can fall a lot before you make a loss.

These ideas assume that selling price and variable cost per unit stay constant, and that fixed cost stays constant in the range considered. Say this if the question asks for limitations.

Key rules to remember

Contribution
Contribution = Sales − Variable cost = Fixed cost + Profit
Per unit: Contribution per unit = Selling price per unit − Variable cost per unit.
P/V ratio
P/V ratio = (Contribution ÷ Sales) × 100
Also = (Change in profit ÷ Change in sales) × 100, when fixed cost is unchanged.
Break-even sales
BEP (₹) = Fixed cost ÷ P/V ratio; BEP (units) = Fixed cost ÷ Contribution per unit
Use the ratio in decimal or fraction form when dividing.
Margin of safety
MOS (₹) = Actual sales − BEP sales = Profit ÷ P/V ratio
MOS ratio = MOS ÷ Actual sales × 100.
Sales for desired profit
Required sales = (Fixed cost + Desired profit) ÷ P/V ratio
Units = (Fixed cost + Desired profit) ÷ Contribution per unit.
Profit from sales
Profit = Sales × P/V ratio − Fixed cost
Works when sales and P/V ratio are known.
Variable cost ratio
Variable cost ratio = 100% − P/V ratio
Check: P/V ratio + variable cost ratio = 100%.

How to solve Cost-Volume-Profit Analysis and P/V Ratio questions

Use this order for any CVP question. It keeps the working short and earns step marks.

  1. 1Write down all given data: sales, variable cost, fixed cost, profit, units, price.
  2. 2Check whether costs are given as fixed, variable or semi-variable. Split semi-variable costs first.
  3. 3Compute contribution (total or per unit) as Sales − Variable cost.
  4. 4Compute the P/V ratio. If two periods are given, use change in profit ÷ change in sales.
  5. 5Find fixed cost: Contribution − Profit, or from the two-period method.
  6. 6Find break-even sales using Fixed cost ÷ P/V ratio.
  7. 7Apply the specific ask: margin of safety, sales for target profit, or effect of a change in price or cost. Recompute contribution if price or variable cost changes.
  8. 8State the answer with units and a one-line interpretation.

Quickest way: P/V ratio first, then everything follows

When to use it: Use for MCQs and for the first lines of a written answer when sales, variable cost or two periods of profit are given.

  1. Get P/V ratio in the simplest fraction, such as 40% = 2/5. Fractions are faster than decimals.
  2. Profit gap trick: Change in profit ÷ Change in sales gives P/V ratio directly, with no need for fixed cost.
  3. Fixed cost = Sales × P/V ratio − Profit, using any one period.
  4. Break-even sales = Fixed cost ÷ P/V ratio. Margin of safety = Profit ÷ P/V ratio.
  5. In MCQs, test each option by checking contribution = fixed cost + profit. Discard options that fail.
  6. In written answers, show a small table: Sales, Variable cost, Contribution, Fixed cost, Profit. Then the formula, substitution and answer, so each step earns marks.

Common mistakes in Cost-Volume-Profit Analysis and P/V Ratio

  • Using profit instead of contribution to find the P/V ratio.

    Students remember 'P/V' and think it means profit ÷ volume.

    Fix: P/V ratio = Contribution ÷ Sales. Profit alone ignores fixed cost.

  • Treating fixed cost as changing with output in the break-even formula.

    Per-unit fixed cost from an earlier costing topic gets carried over.

    Fix: Use total fixed cost in CVP. It is constant in total within the relevant range.

  • Taking the change in profit ÷ change in sales method when fixed cost has also changed.

    The shortcut is memorised without its condition.

    Fix: Use it only when fixed cost is the same in both periods. Otherwise adjust for the fixed cost change.

  • Not recomputing the P/V ratio after a change in selling price.

    Students keep the old ratio from part (a) in part (b).

    Fix: A price change alters contribution per unit and sales. Rebuild contribution and the ratio each time.

  • Calculating margin of safety as BEP minus actual sales.

    The order of subtraction is mixed up.

    Fix: MOS = Actual (or budgeted) sales − BEP sales. It should be positive when the firm is making a profit.

  • Forgetting that variable selling expenses are part of variable cost.

    Only production costs are marked as variable.

    Fix: Include variable selling and distribution costs, such as commission on sales, when computing contribution.

Worked examples

Example 1

A company has sales of ₹10,00,000, variable cost of ₹6,00,000 and fixed cost of ₹2,40,000. Calculate (a) P/V ratio, (b) break-even sales, (c) profit, (d) margin of safety and its ratio.

Show the solution
  1. Contribution = 10,00,000 − 6,00,000 = ₹4,00,000.
  2. (a) P/V ratio = 4,00,000 ÷ 10,00,000 × 100 = 40%.
  3. (b) Break-even sales = 2,40,000 ÷ 0.40 = ₹6,00,000.
  4. (c) Profit = Contribution − Fixed cost = 4,00,000 − 2,40,000 = ₹1,60,000.
  5. (d) Margin of safety = 10,00,000 − 6,00,000 = ₹4,00,000. Check: Profit ÷ P/V ratio = 1,60,000 ÷ 0.40 = ₹4,00,000.
  6. MOS ratio = 4,00,000 ÷ 10,00,000 × 100 = 40%.

Answer: P/V ratio 40%; break-even sales ₹6,00,000; profit ₹1,60,000; margin of safety ₹4,00,000 (40% of sales).

Example 2

A firm's sales and profit were: Year 1 sales ₹8,00,000, profit ₹60,000. Year 2 sales ₹10,00,000, profit ₹1,00,000. Fixed cost is the same in both years. Find (a) P/V ratio, (b) fixed cost, (c) break-even sales, (d) sales needed for a profit of ₹1,50,000.

Show the solution
  1. (a) Change in profit = 1,00,000 − 60,000 = ₹40,000. Change in sales = 10,00,000 − 8,00,000 = ₹2,00,000.
  2. P/V ratio = 40,000 ÷ 2,00,000 × 100 = 20%.
  3. (b) Year 2 contribution = 10,00,000 × 20% = ₹2,00,000. Fixed cost = 2,00,000 − 1,00,000 = ₹1,00,000. Check with Year 1: 8,00,000 × 20% = 1,60,000; 1,60,000 − 60,000 = ₹1,00,000.
  4. (c) Break-even sales = 1,00,000 ÷ 0.20 = ₹5,00,000.
  5. (d) Required sales = (1,00,000 + 1,50,000) ÷ 0.20 = 2,50,000 ÷ 0.20 = ₹12,50,000.

Answer: P/V ratio 20%; fixed cost ₹1,00,000; break-even sales ₹5,00,000; sales for ₹1,50,000 profit ₹12,50,000.

Exam tips

  • Show the contribution line first in every written answer. Examiners give marks for it even if a later step goes wrong.
  • In MCQs, work with fractions of P/V ratio. Most options differ by a clear margin, so rough working is enough to eliminate.
  • Read whether the question gives actual sales or budgeted sales before computing margin of safety.
  • For 'what if' questions on price, volume or cost changes, make a fresh contribution statement for the new situation.
  • A one-line interpretation, such as 'sales can fall by 40% before a loss', makes the answer complete.

Practice questions from Marginal Costing

Cost-Volume-Profit Analysis and P/V Ratio in other exams

The same ground in other exams, if you are preparing for more than one or want another angle on it.

Cost-Volume-Profit Analysis and P/V Ratio: frequently asked questions

What is the difference between P/V ratio and contribution margin ratio?

They are the same thing. Both equal contribution divided by sales, shown as a percentage. ICAI questions use either name.

How do I find the P/V ratio when fixed cost is not given?

Use two periods. Divide the change in profit by the change in sales. This works only if fixed cost is the same in both periods.

Can margin of safety be calculated from profit?

Yes. Margin of safety in rupees equals profit divided by the P/V ratio. It gives the same answer as actual sales minus break-even sales.

What happens to P/V ratio if selling price rises and costs stay the same?

Contribution per unit rises by the full price increase, and the ratio improves. Recalculate it with the new price and the same variable cost per unit.