Guides/Percents that add to 100

Split percentages that add to 100

Budgets, survey charts, and cost shares need parts thatsum to 100%. Raw ratios rarely land on neat integers — you normalize, then fix rounding.

Normalize raw weights

• Weights 2, 2, 1 → total 5 → percents 40%, 40%, 20%.
• Percent_i = (weight_i ÷ sum) × 100
• “What percent is X of Y” building block:X as % of Y.

Rounding so the pie closes

1. Compute exact percents; round to whole numbers.
2. If they sum to 99 or 101, nudge the largest remainder (or largest share) by 1 point.
3. Dollar splits with tip use money rounding carefully —split bill with tip.

Worked budget

Spend $500, $300, $200 → 50%, 30%, 20%. If one category changes, recompute from new totals rather than editing one percent in isolation —% of a number.

Calculator

Percentage Calculator

Common mistakes

• Editing one slice’s percent without renormalizing the others.
• Mixing “percent of total” with “percent change” language.
• Leaving rounded slices at 99% or 101% on a published chart.