Here are 28 digits.

Must be more than on Granny's calculator:

DECLARE @Amount MONEY, @Term INT

DECLARE @fRate float, @dRate decimal (38,28)

DECLARE @i INT, @fOutput FLOAT, @dOutput DECIMAL (38,28)

SELECT @Amount = 1000000, @Term = 12*17

SELECT@fRate = CONVERT(FLOAT, @Amount)/@Term,

@dRate = CONVERT(DECIMAL(38,28), @Amount)/@Term

SELECT@fOutput = @fRate * @Term,

@dOutput = @dRate * @Term

SET @I = 5

WHILE @i > 0

BEGIN

SET @fOutput = @fOutput / @fRate /@Term * @fRate * @Term

SET @dOutput = @dOutput / @dRate /@Term * @dRate * @Term

SET @I = @I - 1

END

SELECT@fOutput [@fOutput] , SQL_VARIANT_PROPERTY(@fOutput, 'MaxLength'), @dOutput [@dOutput], SQL_VARIANT_PROPERTY(@dOutput, 'MaxLength')

I must have tried to make FLOAT to show any weakness.

Did not happen.

In the last example I made the list shorter, to make the case more "real-life".

Did not help much.

DECIMAL is still proven to be too imprecise.