Inside waistband wear

[CDNSushi]

I want to carry a sgian-dubh and a flask in a sheath/pouch positioned inside my waistband. That is a little bulky, so do I need to increase the waist measurement to accommodate it? Or are kilts as forgiving as trousers in this regard?

Why on earth would you wish to carry your sgian inside your waistband? That would be highly unusual, and to anyone witnessing you doing so, probably rather comical too. Sgian gets tucked into your hose, and the flask goes into the sporran...