Milligrams per milliliter equal the percent times ten. A 1.8 mL cartridge holds that concentration times 1.8. The weight-based maximum is milligrams per kilogram times body weight. If that figure is above the absolute cap, the cap is the maximum. Cartridge count is the maximum milligrams divided by milligrams per cartridge.
A 70 kg adult and lidocaine 2% with epinephrine, at 7 mg/kg and a 500 mg cap, is 490 mg. That is under the cap. At 100 kg the weight-based figure is 700 mg, so the calculator uses the 500 mg cap. Bupivacaine 0.5% at 2 mg/kg has a 90 mg cap, so 70 kg is 90 mg, or 10 cartridges of 1.8 mL at 9 mg each.
Lidocaine 2% with epinephrine: 7 mg/kg, absolute cap 500 mg.
Articaine 4% with epinephrine: 7 mg/kg, absolute cap 500 mg.
Mepivacaine 3% plain: 6.6 mg/kg, absolute cap 400 mg.
Prilocaine 4%: 8 mg/kg, absolute cap 600 mg.
Bupivacaine 0.5% with epinephrine: 2 mg/kg, absolute cap 90 mg.
Follow current references and clinical judgment. These figures are study calculations, not a prescription.