| Result seems too large | The percentage may have been entered as 25 instead of 0.25 in a formula that already divides by 100. | Use the tool percentage input as labeled, and confirm displayed formula and result. |
| Result seems too small | The whole or percentage input may be in the wrong field. | Match the selected mode with the correct reference whole and rate. |
| Unexpected negative result | New and old values may be reversed, or the value genuinely declined. | Verify entry order and interpret the sign using the chosen mode. |
| Percentage change shows undefined | The original value is zero. | Use absolute change or another defined business metric. |
| Percent of a whole is greater than 100 | The part may exceed the selected whole or an incorrect denominator was used. | Check whether values and populations are comparable. |
| Percentage difference disagrees with change | The two operations use different denominator conventions. | Use change for a baseline and symmetric difference for two neutral measurements. |
| Percentage points disagree with relative change | Point difference and percent growth are different metrics. | Subtract the rates for percentage points; divide by baseline rate for relative change. |
| Reverse discount value looks wrong | The discount was subtracted from the reduced price. | Divide final price by 1 minus the discount rate. |
| Reverse calculation impossible | A 100% reduction or zero factor eliminates information. | Explain that the original cannot be uniquely recovered from the final value. |
| Discount stacking appears incorrect | Discount percentages were added instead of multiplied. | Multiply remaining-price factors one by one. |
| Markup and margin disagree | Markup uses cost, margin uses selling price. | Confirm the intended denominator and compare both formulas. |
| Target margin gives a surprising price | The target margin was treated as markup. | Use Cost divided by 1 minus the desired margin as a decimal. |
| Tax-inclusive total differs | The selected tax rate or taxable base may be wrong. | Verify jurisdiction-specific tax rules and use the correct base. |
| GST calculation differs from invoice | Tax classification, cess, discounts or rounding can vary. | Check current official tax rules and invoice-level rounding. |
| Tip total differs from the restaurant | The tip may be based on pre-tax versus post-tax amount. | Check receipt settings and whether service fees are included. |
| Commission payment differs | The contract may exclude refunds, taxes or noneligible sales. | Recalculate using the agreement-defined commission base. |
| Salary hike amount differs from payslip | The change may apply only to basic pay or another salary component. | Confirm the employer’s salary definition and payroll deductions. |
| ROI differs from reporting dashboard | Investment cost, fees or net gains may be defined differently. | Reconcile source amounts and accounting definitions. |
| CTR differs from analytics software | Platform counting and reporting windows may differ. | Check clicks, impressions, date range and data source. |
| Conversion rate is unexpectedly high | Numerator and denominator may use unrelated scopes. | Match conversions to clicks, users or sessions as intended. |
| Retention and churn do not total 100 | New or reactivated customers or different cohorts may be included. | Calculate both on the same defined cohort and interval. |
| Decimal conversion appears off by 100 | A percentage was not divided by 100 or a decimal was converted twice. | Confirm whether the displayed input is a percentage or decimal. |
| Fraction is rounded | The entered percentage may be an approximation to a repeating fraction. | Use exact fractional data when available and review chosen precision. |
| Chart looks strange with negative values | Part-to-whole charts can be unsuitable for signed metrics. | Rely on the numeric output and select an appropriate comparison visualization. |
| Calculation history is missing | Browser data or private-session storage may have been cleared. | Use exported records for important results and confirm storage settings. |
| Favorite does not persist on a different device | Browser-local favorites do not necessarily sync. | Export or share the calculation through an approved method. |
| Bulk results have inconsistent precision | Rows may have different input formats or rounding. | Normalize data and validate sample rows before export. |
| CSV columns are interpreted as dates | Spreadsheet software may infer data types unexpectedly. | Import the CSV with explicit field formats and verify columns. |
| PDF export loses layout | Print or export rendering may vary by browser. | Inspect PDF preview, page size and margins before saving. |
| Shared result does not show expected values | Share state may differ from exported or copied output. | Reopen the shared destination and verify displayed inputs. |
| Number becomes NaN or invalid | A nonnumeric character or incomplete field may have been entered. | Remove formatting, check separators and enter valid numbers. |
| Large values show rounded results | Floating-point precision or display formatting may limit exactness. | Keep adequate precision, use appropriate rounding and cross-check material figures. |
| I cannot find my exact calculation mode | The current tab may group financial or business operations separately. | Inspect Percentage, Finance, Business and Convert & Table tabs. |
| No result appears | A required input may be blank or invalid. | Complete all relevant fields and check the step view. |
| Percentage calculation and tax advice conflict | The calculator computes arithmetic but does not establish legal tax treatment. | Consult current official tax guidance or a qualified adviser for the applicable rule. |