Local Anesthetic Maximum Dose Calculator — Lidocaine, Bupivacaine, Ropivacaine
Calculate the maximum safe dose of a local anesthetic — lidocaine, bupivacaine, ropivacaine, mepivacaine or chloroprocaine, plain or with epinephrine — in mg and in mL of your solution strength.
How it works
Maximum dose (mg) = the lower of mg/kg limit × weight (kg) and the absolute ceiling. Volume (mL) = dose (mg) ÷ (strength % × 10). Limits used: lidocaine 4.5 mg/kg (300 mg), with epinephrine 7 mg/kg (500 mg); bupivacaine 2.5 mg/kg (175 mg), with epinephrine 3 mg/kg (225 mg); ropivacaine 3 mg/kg (200 mg); mepivacaine 5 mg/kg (400 mg); chloroprocaine 11 mg/kg (800 mg), with epinephrine 14 mg/kg (1,000 mg).
Maximum recommended doses aim to avoid local anesthetic systemic toxicity (LAST) — perioral tingling, tinnitus and seizures progressing to arrhythmia and cardiac arrest. Epinephrine slows absorption and raises the ceiling for lidocaine, bupivacaine and chloroprocaine. Figures differ slightly between labels and textbooks; risk also depends on the injection site (intercostal and epidural blocks absorb fastest), age, pregnancy, heart, liver and kidney disease. Doses of different local anesthetics given together are additive.
Worked example
For a 70 kg adult and plain lidocaine 1%: 4.5 mg/kg × 70 kg = 315 mg, above the 300 mg ceiling, so the maximum dose is 300 mg. At 10 mg/mL that is 30.0 mL of 1% lidocaine.
Sources: StatPearls — Local Anesthetic Toxicity · University of Iowa — Maximum recommended doses of local anesthetics
Frequently asked questions
How many mg are in 1 mL of a 1% solution?
A 1% solution contains 1 g per 100 mL, which is 10 mg/mL. So 2% = 20 mg/mL, 0.5% = 5 mg/mL and 0.25% = 2.5 mg/mL.
Are doses of two local anesthetics additive?
Yes. When mixing drugs, add each as a fraction of its own maximum; the fractions together should not exceed 1 (100%).
What are the signs of local anesthetic toxicity?
Early signs include a metallic taste, perioral numbness, tinnitus, dizziness and agitation, then seizures, arrhythmias and cardiovascular collapse. Treatment includes stopping injection, airway support, seizure control and 20% lipid emulsion.
Which weight should I use in obesity?
Many references recommend lean or ideal body weight, because plasma levels do not rise in proportion to fat mass. Use your institution’s guidance.
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For trained clinicians only. Always confirm doses and measurements against the product label, local protocol and the full clinical picture — this calculator does not replace professional judgement.