Well sort of @dennisedson. I've had another look at the above and it's only caluclating the 'ft' not inches. Howver using the below is a lot more accurate...
{% for row in housetype_db %}
<!-- Convert mm to ft & inches -->
{% set inches = (row.gf_kitchen_met_1 / 25.4) %}
{% set feet = (inches / 12)|round(0, 'floor') %}
{% set measurement = (inches % 12)|round(0) %}
<!-- Run calculation -->
{% if measurement >= 12 %}
<p>{{ feet + 1 }}'0"</p>
{% else %}
<p>{{ feet }}'{{ measurement }}"</p>
{% endif %}
{% endfor %}