MROUND in Apple Numbers: Nearest Multiple and Halfway Ties

MROUND selects the nearest multiple of a factor. Halfway between two multiples, Apple says it rounds away from zero: =MROUND(4.5,3) → 6 and =MROUND(-4.5,-3) → -6. [A1]

Copyable formula for English/decimal-point locale:

=MROUND(12,5)

For 12 and 5 the expected result is 10 (computed independently). [M1]

Find the two multiples of the factor that bracket the input and choose whichever is closer. If they are exactly equally distant, choose the multiple farther from zero. For signed inputs the factor must have the same sign. [A1, M1]

These are multiple-based operations. To round to a chosen number of decimal places instead, use a separate documented function such as ROUND, and do not assume that specifying a factor such as 0.01 is always equivalent at a floating-point edge case. [A6]

=MROUND(num-to-round, factor)

num-to-round is a required number to be rounded. factor is a required number specifying the interval between accepted results. Apple states that factor must have the same sign as the value being rounded. No default for either argument is documented; no optional third “mode” argument is documented. Apple’s signature explicitly marks two numeric argument slots. Arguments occur in this order: value first, factor second. This guide does not assume text conversion, missing values, arbitrary array arguments, or extra undocumented options. [A1, A2]

Independent mathematical interpretation

For nonzero numbers and factors of matching sign, the independent mathematical rule is SIGN(value) × round_half_up(ABS(value)/ABS(factor)) × ABS(factor), where round_half_up rounds positive half-integer quotients upward. Here “half up” on the positive quotient corresponds to ties away from zero on the original signed number. This arithmetic was calculated with Python Decimal and was not run in Numbers. [A1, M1]

Apple’s current English Formulas and Functions Help, accessed 2026-10-12T04:45:32Z, is the source of this function’s spelling, argument names and sample results. The separately checked Numbers User Guide for Mac identifies the Mac guide as Numbers 15.4. That does not prove this function’s minimum introduction version, old iOS behaviour, or identical iCloud execution. Apple’s shared formula help says it applies to Numbers, Pages and Keynote tables, including Numbers on iPhone, iPad, Mac and in supported cloud use; historical feature parity was not retested. No alternate localized function names were independently verified, so none are presented as aliases. [A1, A4, A5]

The examples assume a locale using periods for decimals and commas for function separators. Apple’s Functions overview explicitly says that when the system uses a comma as the decimal separator, typed function arguments are separated by a semicolon. With num-to-round=12 and factor=5, write =MROUND(12;5) in such a locale, changing MROUND to the function on this page. Use the Numbers formula editor if your region inserts punctuation differently; don’t paste formulas containing thousands separators as numeric literals. English function names are case-insensitive per Apple. [A2]

In a Numbers table, B2 means cell B2 of the current table, and B2:B8 is a range. A different table may need a qualified reference such as Table 2::B5; a different sheet can require Sheet 2::Table 2::B5. These are Numbers examples from Apple’s cell reference guide. The Sheet1!B2 notation common in Excel is not the reference style to copy into Numbers. Here each argument is one scalar numeric cell, not a range. [A3]

Validation labels: Apple reference checked = documentation checking. Numerical outputs = independent Python Decimal calculation unless an official Apple example is explicitly identified. No function or screenshot was run or captured in the Apple Numbers app. All worksheet values below are expected, not observed native results.

Create a fresh Numbers table named RoundingPractice and give it at least eight data rows. Set B1 to Value, C1 to Factor, and D1 to MROUND result. Enter columns B and C from the table below, then enter the expression in D2 and fill D2 through D9. Ensure negative values and negative factors both use the literal minus character -. With the default English punctuation, Numbers should treat each pair as numeric. The results are independent expected results, not observed native execution. [A1, A3, M1]

Row: 2

B: Value
12

C: Factor
5

D formula
=MROUND(B2,C2)

Expected D
10

Row: 3

B: Value
12.5

C: Factor
5

D formula
=MROUND(B3,C3)

Expected D
15

Row: 4

B: Value
15

C: Factor
5

D formula
=MROUND(B4,C4)

Expected D
15

Row: 5

B: Value
-12

C: Factor
-5

D formula
=MROUND(B5,C5)

Expected D
-10

Row: 6

B: Value
-12.5

C: Factor
-5

D formula
=MROUND(B6,C6)

Expected D
-15

Row: 7

B: Value
7.1

C: Factor
0.5

D formula
=MROUND(B7,C7)

Expected D
7.0

Row: 8

B: Value
-3.2

C: Factor
-2

D formula
=MROUND(B8,C8)

Expected D
-4

Row: 9

B: Value
0.25

C: Factor
1

D formula
=MROUND(B9,C9)

Expected D
0

To isolate input issues, start by typing =MROUND(12,5) into any empty cell. Then try =MROUND(-12,-5) in another; those two standalone formulas do not depend on table names or reference formatting.

Apple’s own short examples

The following are documented examples on the cited official function page, not independently observed Numbers outputs. They were also recomputed mathematically for this review. [A1, M1]

For an explicitly agreed policy of nearest 0.05-unit rounding, =MROUND(4.42,0.05) has an independently calculated expected output 4.40; =MROUND(4.43,0.05) → 4.45. This illustrates an arithmetic rule only: whether a particular purchase, tax, invoice or payment should be rounded this way depends on local rules and your contract. Avoid asserting a universal legal cash-rounding rule from a spreadsheet function. [A1, M1]

If shipping lanes are grouped into 3-unit steps, =MROUND(4.4999,3) is expected to return 3, while =MROUND(4.5,3) is 6 under Apple’s exact-tie rule. In a real threshold decision, rounding to nearest is not a safe substitute for always rounding up to cover minimum required capacity. [A1, M1]

For a positive source input B2 and valid factor C2, keep the original in column B and the MROUND formula in column D. In E2, calculate:

=D2-B2

For the first worksheet row (B2=12, C2=5) the expected adjustment is 10 - 12 = -2. A positive adjustment means the rounded result is larger on the number line; a negative adjustment means smaller. A signed negative input may reverse the relationship between numeric direction and magnitude, so compare absolute magnitudes if that is what your business process cares about.

A second diagnostic is whether a value was already an exact accepted multiple: for positive inputs with whole-number factor, test D2=B2 in a separate cell; this checks whether the rounded output changed, not whether input validation succeeded. These diagnostic expressions are elementary arithmetic and logical comparisons; they have not been tested inside Numbers.

• Halfway tie: =MROUND(4.5,3) → 6. The corresponding negative formula =MROUND(-4.5,-3) → -6. Both are official Apple examples.
• Just below a tie: =MROUND(4.4999,3) → 3 and =MROUND(-4.4999,-3) → -3; these avoid an ambiguity about tie direction.
• Different signs: =MROUND(-4.5,3) returns an error according to Apple. Apple’s cited article does not name an English error token: do not label it #NUM! without native Numbers verification.
• Already exact: =MROUND(15,5) should mathematically remain 15.
• Zero factor / zero input: not natively tested, and the selected Apple article does not provide a definitive edge-case matrix; do not infer Numbers behaviour from Excel or Google Sheets.
• Decimal precision: while decimal inputs work in Apple’s examples, floating-point storage may affect borderline values in some spreadsheet implementations. A targeted Numbers execution is needed before guaranteeing tricky decimal halfway cases in production. [A1, A6, M1]

If your result is not what you expected

1. Check the factor’s sign. For nonzero inputs, the official requirement is same sign as the value. Do not mechanically use positive factors for negative inputs.
2. Check whether you chose the right rounding direction. One of the three functions may be conceptually wrong even when its formula is accepted.
3. Check locale punctuation. A user with comma decimals must use semicolon argument separators when entering formulas manually, according to Apple.
4. Check Numbers table references. Same-table B2 is fine; Excel-style sheet exclamation marks should not be imported uncritically.
5. Check input types and missing data. The official syntax calls for numbers; parse currency-formatted text or blanks explicitly before relying on them. Exact error messages for invalid text were not tested here.
6. Check extreme precision. Output rounding near an exact multiple can be sensitive to stored values. Review the actual cell’s underlying data rather than only its display format.

For the same valid same-sign input pair, you can contrast expected results as follows. These were computed independently using exact decimal arithmetic, not by executing Numbers:

Value: 12

Factor
5

CEILING
15

FLOOR
10

MROUND
10

Value: 12.5

Factor
5

CEILING
15

FLOOR
10

MROUND
15

Value: 15

Factor
5

CEILING
15

FLOOR
15

MROUND
15

Value: -12

Factor
-5

CEILING
-15

FLOOR
-10

MROUND
-10

Value: -12.5

Factor
-5

CEILING
-15

FLOOR
-10

MROUND
-15

Value: 7.1

Factor
0.5

CEILING
7.5

FLOOR
7.0

MROUND
7.0

Value: -3.2

Factor
-2

CEILING
-4

FLOOR
-2

MROUND
-4

Value: 0.25

Factor
1

CEILING
1

FLOOR
0

MROUND
0

CEILING goes outward from zero, FLOOR goes inward toward zero, and MROUND selects the nearest accepted multiple, with exact halfway ties outward. Because these operations answer different questions, swapping one for another can change packing, pricing or reporting decisions even when the formula runs successfully. [A1, A6, M1]

Microsoft documents MROUND(number,multiple) and, like Apple, a same-sign rule; its help also warns of implementation-dependent midpoint behaviour when the multiple is a decimal fraction (for example 0.1). Therefore do not assume a cross-app decimal midpoint will agree without a targeted test. Apple’s own page defines halfway ties as away from zero. Examples here are native expected outputs based on Apple documentation plus exact decimal arithmetic, not observed cross-app outputs. [E1, A1]

For Google Sheets and other spreadsheet programs, verify the official syntax and negative-input behaviour in the target program before migrating calculations. Merely finding a similarly named function does not prove the same optional arguments, locale punctuation, error tokens or numeric precision. Google Sheets was not executed or independently function-audited in this batch.

• Apple: MROUND reference — primary syntax, required arguments, documented examples and sign rules. [A1]
• Apple: rounding functions comparison — context for selecting the appropriate rounding function. [A6]
• Apple: Functions overview — punctuation, required/optional argument notation and case handling. [A2]
• Apple: refer to cells in formulas — Numbers-style table and sheet references. [A3]
• Microsoft: Excel MROUND function — source for the explicit Excel comparison; do not interpret as an Apple manual. [E1]

Claim-level evidence IDs

[A1] Apple MROUND official reference: https://support.apple.com/guide/functions/mround-ffa59247cb/web (syntax, sign rules, meaning, documented outputs; accessed 2026-10-12T04:45:32Z).

[A2] Apple Functions overview: https://support.apple.com/guide/functions/functions-overview-ffa083bef0c/web (argument notation, locale punctuation, case; accessed 2026-10-12T04:45:32Z).

[A3] Apple Refer to cells in formulas: https://support.apple.com/guide/functions/refer-to-cells-in-formulas-ffa550d691/web (same-table cells, range syntax, Table 2::B5 qualified references; accessed 2026-10-12T04:45:32Z).

[A4] Apple Formulas and Functions Help: https://support.apple.com/guide/functions/welcome/web (app/platform scope and catalogue; accessed 2026-10-12T04:45:32Z).

[A5] Apple Numbers User Guide for Mac: https://support.apple.com/guide/numbers/welcome/mac (Mac guide labelled 15.4 at access; other editions unverified; accessed 2026-10-12T04:45:32Z).

[A6] Apple Functions used to round values: https://support.apple.com/guide/functions/functions-used-to-round-values-ffa5bf6af47/web (different rounding families; accessed 2026-10-12T04:45:32Z).

[E1] Microsoft official Excel MROUND: https://support.microsoft.com/en-us/excel/functions/mround-function (Excel-only signature/behaviour and platform scope; accessed 2026-10-12T04:45:32Z).

[M1] Independent exact-decimal arithmetic: Python stdlib decimal, with input/output rows and method stored in supporting calculation records; verified 2026-10-12T04:45:32Z. Does not prove Numbers’ implementation.

• EVEN — continue with a related Apple Numbers calculation.
• ODD — continue with a related Apple Numbers calculation.
• CEILING — continue with a related Apple Numbers calculation.
• FLOOR — continue with a related Apple Numbers calculation.
• ROUND — continue with a related Apple Numbers calculation.

For a software-specific comparison: LibreOffice Calc MROUND, Apache OpenOffice Calc MROUND, Gnumeric MROUND. A shared name does not establish identical argument, error or version behaviour.

The linked official function documentation was reviewed on October 12, 2026. Apple’s Formulas and Functions Help 15.4 identifies the documentation edition, not a minimum Numbers release or a guarantee of historical platform parity. Selected worked examples were checked using independent mathematical or text-processing models; results are expected values, not observations from the spreadsheet application. Native Apple Numbers execution was not performed. Undocumented coercion, exact error messages and platform-specific behaviour remain unverified.

View reproducible example inputs and independent check results. This record is not a native spreadsheet test log.