Calculation Rules
Middle names are the part of a form nobody reads twice — until numerology insists on counting every letter.
Leave it out, and you're not doing a shortcut. You're doing a different calculation.
Quick answer
Yes, under the standard convention, the destiny number includes the full birth name — first, middle, and last — with no letters skipped. Omitting a middle name will typically change the compound total and can change the final reduced digit.
This describes a calculation convention, not a claim about what any name "should" be or mean.
Overview
Arithmetic can be checked
The standard justification is straightforward: the destiny number is meant to reflect the complete name given at birth, and a middle name is, definitionally, part of that. Skipping it isn't a simplification — it's calculating something else, closer to a partial expression number than a true destiny number.
If you have more than one middle name, all of them get included, in the order they appear on the birth certificate.
Simply calculate using first and last name — there's nothing to add, not a gap to fill.
Most traditions want the full spelled-out name; an initial-only record is usually treated as incomplete for calculation purposes if the full name is available elsewhere.
All letters are typically included; the hyphen itself isn't assigned a value.
Because the calculation is pure addition, adding or removing any set of letters changes the compound total — and a changed total can land on a different final digit after reduction, not just a bigger number along the way.