--- sidebar_position: 145 --- # sumKahan {#agg_function-sumKahan} Calculates the sum of the numbers with [Kahan compensated summation algorithm](https://en.wikipedia.org/wiki/Kahan_summation_algorithm) Slower than [sum](./sum.md) function. The compensation works only for [Float](../../../sql-reference/data-types/float.md) types. **Syntax** ``` sql sumKahan(x) ``` **Arguments** - `x` — Input value, must be [Integer](../../../sql-reference/data-types/int-uint.md), [Float](../../../sql-reference/data-types/float.md), or [Decimal](../../../sql-reference/data-types/decimal.md). **Returned value** - the sum of numbers, with type [Integer](../../../sql-reference/data-types/int-uint.md), [Float](../../../sql-reference/data-types/float.md), or [Decimal](../../../sql-reference/data-types/decimal.md) depends on type of input arguments **Example** Query: ``` sql SELECT sum(0.1), sumKahan(0.1) FROM numbers(10); ``` Result: ``` text ┌───────────sum(0.1)─┬─sumKahan(0.1)─┐ │ 0.9999999999999999 │ 1 │ └────────────────────┴───────────────┘ ```