# reckoner

/ˈɹɛkənəɹ/ (US) · /ɹˈɛkənɐ/ (UK) · CEFR C2 · Noun

Source: https://englishreference.com/word/reckoner
Updated: 2026-10-17

## Definition

a book or table with lists of numbers that helps you calculate things quickly. People used these before calculators existed to find answers for math or money problems.

For teachers: a table or book of pre-calculated values used to facilitate rapid mathematical computation. Often encountered in the compound 'ready reckoner', referring to a reference tool for commercial or technical calculations.

## Examples

- The merchant used a ready reckoner to calculate the tax.
- Before the invention of the electronic calculator, engineers relied on a printed reckoner to determine structural loads.
- The old ledger was accompanied by a tattered ready reckoner, its pages stained from years of use in the bustling dockside counting house.

## Synonyms

table, chart

## Usage notes

- Commonly appears in the fixed phrase 'ready reckoner'.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.