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Pie Chart Data Interpretation: Degrees, Percentages and Amounts

1% = 3.6° • Sector amount • Sector ratios • Changing totals • Two pie charts

SSC Banking 📅 Last updated: 2026-10-24

A pie chart splits one total into parts. Each part's share can be given as a percentage of the total or as a central angle in degrees, and the whole circle is 100% or 360°. Almost every pie chart question in bank and SSC exams reduces to converting between those three forms: percentage, angle and amount.

1% = 3.6°  •  Amount = percentage × total ÷ 100  •  Percentage = angle ÷ 3.6

The chart below shows invented practice data: how a family divides a monthly budget of ₹60,000. The worked examples all use it.

Pie chart: a family's monthly expenditure of ₹60,000 by head30%Food (30%)25%Rent (25%)15%Education (15%)10%Transport (10%)12.5%Savings (12.5%)7.5%Others (7.5%)
Monthly expenditure of ₹60,000 by head.

When the chart gives percentages, find any amount by applying the percentage to the total. Keep the total written at the top of your rough work so you never multiply by the wrong number.

Worked example 1: amount for one sector

Food takes 30% of ₹60,000, which is 30 ÷ 100 × 60,000 = ₹18,000.

Worked example 2: central angle

Rent is 25%, so its sector's angle is 25 × 3.6 = 90°, a quarter of the circle.

Savings, at 12.5%, have an angle of 12.5 × 3.6 = 45°. Recognising common pairs saves time: 10% = 36°, 20% = 72°, 25% = 90°, 50% = 180°.

Worked example 3: angle back to percentage

If a question gives a sector of 54°, its share is 54 ÷ 3.6 = 15%. In this chart, that is Education.

Within one pie chart, every sector shares the same total, so you can compare percentages directly without converting to rupees. Ratios and "how much more" questions become quick.

Worked example 4: one sector more than another

Education is 15% and Transport is 10%. Education spending is more than Transport spending by (15 − 10) ÷ 10 × 100 = 50%.

Worked example 5: ratio of two sectors

Food : Savings = 30 : 12.5. Multiply both by 2 to clear the decimal (60 : 25), then divide by 5: 12 : 5.

Note the difference between "percentage points" and "percent". Food's share is 5 percentage points more than rent's (30 against 25), but food spending is 20% more than rent spending, because 5 is 20% of 25.

Questions get harder when the total changes, either over time or between two charts. The percentages tell you the split; only the total tells you the size.

Worked example 6: same split, bigger budget

Next month the budget rises to ₹72,000 with the same split. Food becomes 30% of 72,000 = ₹21,600, an increase of ₹3,600 over ₹18,000.

Worked example 7: a smaller share can be a bigger amount

A second family spends 25% of ₹80,000 on food: ₹20,000. Its food share is smaller than the first family's 30%, yet it spends more on food, because its total is larger.

When two pie charts appear together, write each chart's total beside it before reading any sector. Then convert each sector you need into an amount and compare amounts, never raw percentages.

A related set shows one chart of percentages and a separate table or bar graph of totals for several years. The method does not change: pick the year's total from the second chart, apply the sector's percentage, and only then compare. If the question asks for a sector's growth between two years and its percentage share stays fixed, the sector grows at the same rate as the total, so you can answer from the totals alone.

  • ✘ Comparing percentages across two pie charts that have different totals.
  • ✘ Dividing an angle by 360 and forgetting to multiply by 100 (or by the total).
  • ✘ Confusing percentage points with percent change.
  • ✘ Forgetting to scale up when the question asks for a yearly figure from a monthly chart.
You haveYou wantDo this
Percentage pAnglep × 3.6
Angle aPercentagea ÷ 3.6
Percentage p and total TAmountp × T ÷ 100
Angle a and total TAmounta × T ÷ 360
Two sectors of one chartRatioRatio of their percentages

Pie charts are often paired with a bar graph or a table in mixed DI sets. For faster percentage arithmetic, see approximation for DI and the ratio basics; more shortcuts are in the Quant cheat code.

Q1. Using the pie chart of a ₹60,000 monthly budget, how much does the family spend on rent? easy

✅ Answer: (c) ₹15,000

💡 Explanation: Rent is 25% of the total, and 25% of ₹60,000 is ₹15,000. ₹18,000 is the food figure, at 30%.

Q2. What is the central angle of the Transport sector? easy

✅ Answer: (a) 36°

💡 Explanation: Each 1% of a pie is 3.6 degrees, because 360 ÷ 100 = 3.6. Transport is 10%, so its angle is 10 × 3.6 = 36°.

Q3. How much does the family spend on Education and Others together each month? medium

✅ Answer: (d) ₹13,500

💡 Explanation: Education (15%) and Others (7.5%) together make 22.5% of the budget. 22.5% of ₹60,000 = ₹13,500.

Q4. If the pattern stays the same every month, how much does the family save in a year? medium

✅ Answer: (b) ₹90,000

💡 Explanation: Monthly savings are 12.5% of ₹60,000 = ₹7,500. Over 12 months that is ₹90,000. ₹7,500 is the trap if you stop at one month.

Q5. By how many rupees does monthly spending on food exceed spending on rent? easy

✅ Answer: (b) ₹3,000

💡 Explanation: The gap is 30% − 25% = 5 percentage points of the budget, and 5% of ₹60,000 = ₹3,000. Subtracting the percentages first saves a multiplication.

Q6. In a pie chart of the same ₹60,000 budget, a sector has a central angle of 63°. What amount does it represent? hard

✅ Answer: (a) ₹10,500

💡 Explanation: A sector's share is its angle divided by 360. So 63 ÷ 360 × 60,000 = ₹10,500, which is 17.5% of the budget.

How do I convert a pie chart angle into a percentage quickly?

Divide the angle by 3.6, because a full circle of 360 degrees is 100 percent. So 72 degrees is 20 percent and 90 degrees is 25 percent. To go the other way, multiply the percentage by 3.6.

Can I compare sectors from two different pie charts directly?

Only if both charts have the same total. A smaller percentage of a larger total can be a bigger amount, so always convert each sector into an actual amount using its own chart's total before comparing.

All problems and solutions on this page are original. No outside facts are relied on; every numeric answer is recomputed by software before publishing.

How this page was prepared. Drafted with AI assistance (Claude (Anthropic AI model)) from the sources listed above. 14 calculations on this page were recomputed by software and matched. Automated checks also covered structure, internal links and duplicate text. Software checks cannot confirm facts. Reviewed by praveenkumar on 2026-10-24 against the sources listed above.

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