Input
Output
Raw percent
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Rounded percent
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Delta (rounded − raw)
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Equivalent rounded value (uses base if provided)
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Formula used
p is the percent. If you enter a value and base, then p = (value / base) × 100.
With a step increment s (percent units), scale to q = p / s. Depending on rounding mode:
- Nearest (half up): q̂ = round_half_up(q), so p̂ = q̂ × s.
- Up (toward +∞): q̂ = ceil(q), so p̂ = q̂ × s.
- Down (toward −∞): q̂ = floor(q), so p̂ = q̂ × s.
- Bankers: ties round to the nearest even integer: q̂ = round_to_even_on_tie(q).
Without a step (s = 0), round p directly to d decimals using the same mode. The rounded value from a base is valuê = base × p̂ / 100.
How to use this calculator
- Choose whether you have a percentage or a value and base.
- Set decimal places for display precision.
- Optionally choose a step increment like 0.1, 0.25, 0.5, or 1.
- Select a rounding mode that fits your policy.
- Press Calculate to see results, then Add to table.
- Export your table as CSV or PDF for records.
Results table
| # | Input type | Percent (%) | Step (%) | Decimals | Mode | Rounded (%) | Delta (%) | Base | Rounded value | Time |
|---|
Example data table
Preloaded examples demonstrate common scenarios, including bankers ties and step increments.
| # | Scenario | Input | Settings | Raw (%) | Rounded (%) |
|---|
FAQs
Turning a percentage to a preferred resolution using a rule. You choose decimal places or step increments and a rounding mode like nearest, up, down, or bankers.
Use decimals to control shown precision, like whole percent or 0.1%. Use a step to snap to increments, like 0.5% or 2.5%, before formatting.
Bankers rounding resolves .5 ties toward the nearest even number. It reduces cumulative bias over many rounded values, useful in analyses and reports.
Nearest uses symmetric half up logic. Up means toward +∞, while down means toward −∞. Bankers keeps the even rule at exact .5 ties regardless of sign.
Yes. Enter 2.5 as the step increment. The percent snaps to the nearest multiple of 2.5% using your chosen rounding mode.
Results use double precision arithmetic and careful tie handling. For display, you control decimal places to match reporting requirements.
Use the green button for CSV and the red button for PDF. Your current table is converted and downloaded locally without sending data anywhere.
Rounding mode behavior at ties
Comparison at .5 step ties for positive and negative values.
| Raw (%) | Step (%) | Nearest | Up | Down | Bankers |
|---|
Typical step increments and precision policies
Reference only. Choose settings matching your reporting standards.
| Use case | Recommended step (%) | Typical decimals | Notes |
|---|---|---|---|
| Retail discount labels | 1.0 | 0 | Whole percents improve readability on signage. |
| Finance rate sheets | 0.25 | 2 | Quarter steps are common for rate quotes. |
| Manufacturing yields | 0.1 | 1–2 | Balance precision with operational reporting speed. |
| Survey rounding | 0.5 | 0 | Half-percent bins smooth minor variation. |
| Executive summaries | 1.0 | 0 | High-level communication favors coarse rounding. |
| Scientific summaries | 0 | 2–4 | No step; use decimals for precise rounding. |