Calculate Missing-Record and Duplicate-Record Rates

Use this calculator

Calculate two clearly defined data-quality rates using separate denominators. Review missing expected records and extra duplicate rows without treating the result as an overall quality score.

Formula and units

Missing-record rate (%) = missing expected records ÷ expected distinct records × 100. Duplicate-row rate (%) = extra duplicate rows ÷ rows reviewed × 100.

Worked example

20 missing records from 1,000 expected distinct records = 2%. Thirty extra duplicate rows in 1,000 reviewed rows = 3%. These rates have different definitions and must not be added.

Inputs and limits

• Expected distinct records in the agreed population: 1 to 1000000000 (whole numbers only).
• Expected records confirmed missing: 0 to 1000000000 (whole numbers only).
• Rows reviewed for duplicates: 1 to 1000000000 (whole numbers only).
• Extra duplicate rows after the first occurrence: 0 to 1000000000 (whole numbers only).

The upper bounds are practical input limits for this tool, not professional standards. Enter decimal numbers using a point, without currency symbols, commas or scientific notation.

Assumptions and interpretation

Agree the population, time window and matching key first. Missing records are absent from an expected population, not rows with blank fields. Count duplicate rows beyond the first occurrence: three copies of one record contribute two extra rows. These inputs may describe different samples; no relationship between the two denominators is assumed. A non-empty reviewed sample always contains at least one first occurrence, so extra duplicate rows must be fewer than reviewed rows. These two rates do not test accuracy, validity or all other quality dimensions.

Rounding and data handling

Calculations use the entered values before rounding. Results display to two decimal places. A tiny non-zero result may display as 0.00; review the input units and magnitude. Financial figures are indicative, not accounting entries. Inputs are processed in browser memory only: this calculator does not submit or store them, and reset or reload clears them. Ordinary website page requests still occur. Do not enter personal or confidential information. Without JavaScript, use the formula and worked example above manually.

These are original RDE planning calculators. Related reading provides context, not validation or endorsement of the formulas or input limits.