Under the column "Yours", provide your familiar's weight.
Click Calculate (Firefox users can simply press enter after typing the weight).
To try different weights simply change the weight and recalculate.
Click [Training Schedule] to show a list of matches at different weights.
Change the amount of risk as needed to balance performance with safety.
Click [Reset] if you'd like to change familiars.
Hints
Add 3 pounds to your familiar to make up for every extra star your opponent has
The ideal excess weight when picking a fight at the same star rating is 3. For low poundage familiars, 2 can be just as good.
Never pick a fight in which your familiar has an X rating
Poundage
adjustment by items: Personal Familiar Equipment, Lead Necklace, Rat
Head Balloon, Plexiglass Pith Helmet, Common Tiny Plastic Equipment (!)
Poundage adjustment by spells: Leash of Linguini, Empathy of the Newt
Poundage adjustment by 'mostly' potions: Knob goblin Pet-buffing Spray, Green Snowcone, Black Snowcone
Advanced Hints
When
there are seemingly no good fights available for your low-poundage
familiar and you can't alter its poundage with items, do this: Find the
fight you would least likely win if it was not against a familiar with
an X rating in that fight. e.g. A fight where you have star rating 1 in
against a 30 lbs familiar that has an x rating in that fight.
Warning: This strategy is unreliable when your familiar is 1-4 pounds
big, it only becomes reliable at poundage 5 (people with Amphibian
Sympathy should never worry)