Math & Trig
FLOOR Function in Excel
Rounds a number down to the nearest multiple of significance.
Syntax
- =FLOOR(number, significance)
Arguments
- number (required): The value to round down
- significance (required): The multiple to round down to
Examples
- =FLOOR(3.7, 1) - Round down to nearest integer - Result: 3
- =FLOOR(4.42, 0.1) - Round down to nearest 0.1 - Result: 4.4
Excel FLOOR function documentation
- FLOOR rounds a number down to the nearest multiple of significance — toward zero for positive inputs in classic FLOOR.
- Syntax: =FLOOR(number, significance). Use for discount tiers, billing increments, and quantity buckets rounded down.
- Category: Math & Trig. Mirror of [CEILING](/functions/ceiling/); pair them when models need both upper and lower bounds.
- For negative numbers or ISO-style rounding, prefer [FLOOR.MATH](/functions/floor-math/) in Microsoft 365 workbooks.
FLOOR function arguments explained
- number (required): the value to round down — price before discount, elapsed time, or inventory count.
- significance (required): the multiple — 1 for whole units, 0.1 for one decimal place as a multiple, 60 for minute blocks.
- Ranges must share the same sign in classic FLOOR; otherwise Excel returns #NUM!.
- Example: =FLOOR(4.42, 0.1) returns 4.4. =FLOOR(47, 10) returns 40 (largest multiple of 10 not exceeding 47).
FLOOR vs FLOOR.MATH vs INT vs TRUNC
- FLOOR — round down to any multiple; legacy sign pairing rules.
- FLOOR.MATH — modern variant with clearer negative-number behavior in M365.
- INT — round down to integer only (toward −∞ for negatives); =INT(4.9)=4, =INT(-4.9)=-5.
- TRUNC — chop decimals toward zero; =TRUNC(-4.9)=-4. Use FLOOR when the step size is not 1.
Billing, discount, and bucket examples
- Hourly billing truncate: =FLOOR(end-start, TIME(1,0,0)) bills complete hours only.
- Age or tenure buckets: =FLOOR(age, 5)*5 groups employees into five-year bands for reporting.
- Promo threshold: =FLOOR(purchase_amount, 25) counts how many $25 blocks qualify for a perk.
- Inventory pick: =FLOOR(available, case_size) shows full cases shippable without breaking packs.
People also ask
- What are the FLOOR function arguments? — number (value) and significance (multiple to round down to).
- FLOOR vs ROUNDDOWN? — FLOOR uses significance multiples; ROUNDDOWN uses decimal places.
- How to round down to nearest 10? — =FLOOR(A1, 10) returns the largest multiple of 10 not greater than A1.
- Why #VALUE! on FLOOR? — Non-numeric text in number or significance; clean data with VALUE first.
Common errors
- #VALUE! if arguments are non-numeric
- Signs must match
Use cases
- Discount calculations
- Time billing
- Quantity adjustments
Frequently asked questions
- How do I round down to the nearest 5 or 10? Use FLOOR with the multiple: =FLOOR(47, 5) returns 45, =FLOOR(47, 10) returns 40. This is useful for pricing tiers, age groups, or any bucketing by fixed intervals.
- What's the difference between FLOOR and INT? INT always rounds down to the nearest integer. FLOOR rounds down to any multiple you specify. =INT(4.7)=4, =FLOOR(4.7, 0.5)=4.5. Use INT for integers, FLOOR for custom multiples.
- How do I round time down to the nearest hour? Use =FLOOR(A1, TIME(1,0,0)) or =FLOOR(A1, 1/24). This truncates minutes and seconds, keeping only complete hours. Useful for billing in hourly increments.
Editorial review
- Reviewed by Excel.Directory Editorial Team. Updated May 2026.
When to use FLOOR
- Discount calculations — common Math & Trig scenario for FLOOR.
- Time billing — common Math & Trig scenario for FLOOR.
- Quantity adjustments — common Math & Trig scenario for FLOOR.
FLOOR in the Math & Trig category
- Browse all Math & Trig functions at /categories/math-trig/ for related formulas.
- FLOOR syntax: =FLOOR(number, significance)
- number (required): The value to round down
- significance (required): The multiple to round down to
- Confirm FLOOR arguments match the syntax shown above before filling down.
- Lock table and range references with $ when copying formulas across rows or sheets.
Formula checklist before you copy down
- Confirm FLOOR arguments match the syntax shown above before filling down.
- Lock table and range references with $ when copying formulas across rows or sheets.
- If results look wrong, check for text stored as numbers and invisible spaces with TRIM.
- Spot-check three known input rows manually against expected output.
Related Excel functions
- CEILING (/functions/ceiling/): Rounds a number up to the nearest multiple of significance.
- ROUND (/functions/round/): Rounds a number to a specified number of digits.
- ROUNDDOWN (/functions/rounddown/): Rounds a number down, toward zero.
- TRUNC (/functions/trunc/): Truncates a number to an integer by removing the decimal part.
Errors to watch for
- #VALUE! if arguments are non-numeric — review causes on linked error pages in the directory.
- Signs must match — review causes on linked error pages in the directory.
Copy-paste audit workflow
- Enter FLOOR on three test rows with known expected output documented on a QA tab.
- Fill down only after absolute references are locked on lookup tables and rate tables.
- Compare against manual calculation or a calculator for financial and statistical functions.
- Search this directory for comparison guides when choosing between similar functions in the same category.
FLOOR worked examples to copy
- =FLOOR(3.7, 1) — Round down to nearest integer. Expected result: 3.
- =FLOOR(4.42, 0.1) — Round down to nearest 0.1. Expected result: 4.4.
FLOOR reference summary for crawlers and offline review
- FLOOR belongs to the Math & Trig category in Excel. Rounds a number down to the nearest multiple of significance.
- Full syntax: =FLOOR(number, significance). Open /functions/floor/ for parameters, FAQs, and related pages.
- Common mistakes: #VALUE! if arguments are non-numeric; Signs must match
- Pair this function with comparison guides when another Excel formula might fit the same task better.
- Review fix-excel-formula-errors when unexpected errors appear after upgrading Excel or sharing across locales.