These are the most common formulas in a local list. The engine, HyperFormula, supports 418 functions total. Anything not covered below probably still works, it just isn't documented here. See the full list on HyperFormula's docs.

All examples below use this app's own R1C1 reference notation (R1C1, R1C2:R5C2), not the A1-style (B2, B2:B5) notation you'd see in most other spreadsheet docs.

Math & aggregation

• SUM(range) - adds up all the numbers in a range. =SUM(R1C1:R10C1)
• AVERAGE(range) - the mean of a range. =AVERAGE(R1C1:R10C1)
• MIN(range) / MAX(range) - the smallest / largest value in a range.
• COUNT(range) - how many cells in a range contain a number.
• COUNTA(range) - how many cells in a range are non-empty (numbers, text, anything).
• ROUND(value, digits) - rounds to the given number of decimal places. =ROUND(R1C1, 2)
• ROUNDUP(value, digits) / ROUNDDOWN(value, digits) - round away from / toward zero instead of to the nearest.
• ABS(value) - absolute value.
• SQRT(value) - square root.
• POWER(base, exponent) - base raised to exponent.
• MOD(value, divisor) - remainder after division.
• INT(value) - rounds down to the nearest integer.
• TRUNC(value, digits) - cuts off decimal places without rounding.
• MEDIAN(range) - the middle value of a range.
• LARGE(range, n) / SMALL(range, n) - the nth largest / smallest value in a range.
• STDEV(range) - sample standard deviation.
• VAR(range) - sample variance.

Logical

• IF(condition, valueIfTrue, valueIfFalse) - the basic branch. =IF(R1C1>10, "big", "small")
• IFS(condition1, value1, condition2, value2, ...) - chains multiple IFs without nesting.
• AND(condition1, condition2, ...) / OR(condition1, condition2, ...) - true only if all / any conditions are true.
• NOT(condition) - flips a true/false value.
• XOR(condition1, condition2, ...) - true if an odd number of conditions are true.
• IFERROR(value, valueIfError) - swaps in a fallback if value evaluates to an error (including circular-reference errors).
• IFNA(value, valueIfNA) - like IFERROR, but only catches #N/A (e.g. a failed VLOOKUP).
• SWITCH(value, case1, result1, case2, result2, ..., default) - matches value against a list of cases.

Lookup & reference

• VLOOKUP(searchValue, range, columnIndex, [exactMatch]) - finds searchValue in the range's first column, returns a value from columnIndex columns over.
• HLOOKUP(searchValue, range, rowIndex, [exactMatch]) - same idea, but searches the first row instead.
• XLOOKUP(searchValue, searchRange, resultRange, [ifNotFound]) - a more flexible modern replacement for VLOOKUP/HLOOKUP (search and result ranges don't need to be adjacent).
• INDEX(range, row, [col]) - the value at a given row/column offset within a range.
• MATCH(searchValue, range, [matchType]) - the position of searchValue within a range (pair with INDEX for a lookup that isn't limited to searching the first column).
• CHOOSE(index, value1, value2, ...) - returns the nth value from a list.
• ROW([cell]) / COLUMN([cell]) - the row/column number of a cell (or the current cell if omitted).
• ROWS(range) / COLUMNS(range) - how many rows/columns a range spans.

Text

• CONCATENATE(text1, text2, ...) - joins text together. =CONCATENATE(R1C1, " ", R1C2)
• LEFT(text, count) / RIGHT(text, count) - the first / last count characters.
• MID(text, start, count) - count characters starting at position start.
• LEN(text) - the character count of text.
• UPPER(text) / LOWER(text) / PROPER(text) - changes case (all-caps / all-lowercase / Title Case).
• TRIM(text) - strips leading/trailing/repeated whitespace.
• SUBSTITUTE(text, oldText, newText) - replaces occurrences of oldText with newText.
• FIND(needle, text) / SEARCH(needle, text) - the position of needle within text (FIND is case-sensitive, SEARCH isn't).
• TEXT(value, format) - formats a number/date as text, e.g. =TEXT(R1C1, "0.00").
• REPT(text, count) - repeats text count times.

Conditional aggregation

• SUMIF(range, criteria, [sumRange]) - sums cells in sumRange where the matching cell in range meets criteria.
• SUMIFS(sumRange, range1, criteria1, range2, criteria2, ...) - like SUMIF but with multiple criteria that must all match.
• COUNTIF(range, criteria) / COUNTIFS(range1, criteria1, range2, criteria2, ...) - counts matching cells.
• AVERAGEIF(range, criteria, [averageRange]) - averages cells matching a single criterion.
• MAXIFS(maxRange, range1, criteria1, ...) / MINIFS(minRange, range1, criteria1, ...) - max/min of cells matching criteria.
• COUNTUNIQUE(range) - how many distinct values appear in a range.

Date & time

• TODAY() - the current date (no arguments).
• NOW() - the current date and time.
• DATE(year, month, day) - builds a date value.
• YEAR(date) / MONTH(date) / DAY(date) - pulls a component out of a date.
• WEEKDAY(date) - the day of the week as a number.
• EDATE(date, months) - a date months months before/after date.
• NETWORKDAYS(startDate, endDate) - the number of working days (Mon–Fri) between two dates.
• DATEDIF(startDate, endDate, unit) - the difference between two dates in the given unit ("d", "m", "y").

Error & type checking

• ISBLANK(cell) - true if a cell is empty.
• ISERROR(value) - true if value is any error. ISNA(value) - true specifically for #N/A.
• ISNUMBER(value) / ISTEXT(value) - true if value is a number / text.
• TRANSPOSE(range) - flips a range from rows to columns or vice versa.