How to measure without scale :(

So I want to boof. I never thought I’d say this but I am going to put crystal meth in my ass. But I don’t have a fucking scale. Never had one & this continually fucks me over. Should I just try to estimate the equivalent to what I would usually be sniffing? I don’t have a syringe either. I have absolutely none of the tools that I would need to boof but I’m going to do it anyways.