For trained clinicians as a calculation aid. Confirm every dose against the drug label, your own hospital or practice protocol and a second clinician before you give it.
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A local anesthetic maximum is the label limit in mg per kg times the patient's weight, capped at the label's total. For a healthy adult that is 4.5 mg/kg (300 mg at most) for plain lidocaine and 7 mg/kg (500 mg at most) with epinephrine, 7 mg/kg for articaine, 3 mg per lb up to 400 mg for mepivacaine and 8 mg/kg up to 600 mg for prilocaine. Bupivacaine has no per kg figure on its label, only totals: 175 mg plain, 225 mg with epinephrine and 90 mg per dental sitting. To get mL, divide the mg by the concentration, where 1% equals 10 mg/mL.
How to calculate a local anesthetic maximum dose
How this anesthesia dose calculator works: weight times the label mg/kg limit, held under the label's total cap, then turned into mL and cartridges. Any local anesthetic max dose calculator should follow the same three steps.
| Calculation the math behind each result | Chairside meaning why it matters at the chair | |
|---|---|---|
| Weight | lb × 0.453592 = kg | Mepivacaine is labelled per pound, so it is worked in lb |
| Maximum (mg) | The smaller of kg × mg/kg limit and the label total | A heavy patient never pushes the dose past the fixed ceiling |
| Volume (mL) | mg ÷ (concentration % × 10) | 2% is 20 mg/mL, 0.5% is 5 mg/mL |
| Cartridges | mL ÷ cartridge size, rounded down | A part cartridge is shown as a decimal, never rounded up |
| Remaining | Maximum minus mg already given | Every amide you have injected this sitting counts |
Worked example: 70 kg healthy adult, lidocaine 2% with epinephrine, 1.7 mL cartridges
When to use this anesthesia dose calculator
Open it before the first injection, and again whenever the plan changes mid procedure.
- Preoperative planning: work out the ceiling for the block or infiltration before the patient is in the chair. Knowing that a 50 kg patient tops out at about ten 1.7 mL cartridges of 2% lidocaine with epinephrine changes how you split the dose between sites.
- Double checking a dose: a second, independent sum before you draw up.
- Dental appointments: convert the mg ceiling into whole cartridges for the agent on the tray.
- Smaller and pediatric patients: children reach the label limit fast. The age field brings up each label's own pediatric wording, and for mepivacaine and prilocaine it applies the Clark's rule formula the labels print.
- Teaching and training: residents, nurses and dental students can see how weight, concentration and epinephrine move the number, one input at a time.
- Operating room and emergency reference: a quick look at the induction range for propofol or ketamine by weight, with the reduced range for frail and ASA III or IV patients.
- Topping up mid procedure: enter the mg already given to see what is left under the cap.
- Veterinary practice: the limits here come from human drug labels. Animal doses differ by species, so use a veterinary formulary for them and this page only for the arithmetic.
What is the maximum dose of each local anesthetic?
These are the adult maximums printed on each US drug label. The calculator uses the smaller of the per kg figure and the total.
| Agent | Per weight | Total cap | Supplied as |
|---|---|---|---|
| Lidocaine, plain | 4.5 mg/kg | 300 mg | 0.5%, 1%, 1.5%, 2% |
| Lidocaine with epinephrine | 7 mg/kg | 500 mg | 0.5% to 2%; dental 2% in 1.7 mL cartridges |
| Articaine 4% with epinephrine | 7 mg/kg (3.2 mg/lb) | None stated | 1.7 mL cartridges, 68 mg each |
| Mepivacaine 3% | 3 mg/lb (about 6.6 mg/kg) | 400 mg per sitting | 1.7 mL cartridges, 51 mg each |
| Prilocaine 4% | 8 mg/kg (4 mg/lb) | 600 mg (8 cartridges) | 1.8 mL cartridges, 72 mg each |
| Bupivacaine, plain | Not given | 175 mg per dose | 0.25%, 0.5%, 0.75% |
| Bupivacaine with epinephrine | Not given | 225 mg per dose | 0.25%, 0.5%, 0.75% |
| Bupivacaine 0.5% with epinephrine, dental | Not given | 90 mg per sitting | Ten 1.8 mL injections |
Bupivacaine doses may be repeated every three hours, with no more than 400 mg in 24 hours.
How many dental cartridges can a patient have?
Maximum mg and cartridges by weight for a healthy adult, rounded down to a tenth. For any other weight, use the calculator above.
| Weight | Lidocaine 2% with epi, 1.7 mL | Articaine 4%, 1.7 mL | Mepivacaine 3%, 1.7 mL | Prilocaine 4%, 1.8 mL |
|---|---|---|---|---|
| 20 kg (44 lb) | 140 mg · 4.1 | 140 mg · 2.0 | 132 mg · 2.5 | 160 mg · 2.2 |
| 30 kg (66 lb) | 210 mg · 6.1 | 210 mg · 3.0 | 198 mg · 3.8 | 240 mg · 3.3 |
| 40 kg (88 lb) | 280 mg · 8.2 | 280 mg · 4.1 | 264 mg · 5.1 | 320 mg · 4.4 |
| 50 kg (110 lb) | 350 mg · 10.2 | 350 mg · 5.1 | 330 mg · 6.4 | 400 mg · 5.5 |
| 60 kg (132 lb) | 420 mg · 12.3 | 420 mg · 6.1 | 396 mg · 7.7 | 480 mg · 6.6 |
| 70 kg (154 lb) | 490 mg · 14.4 | 490 mg · 7.2 | 400 mg · 7.8 | 560 mg · 7.7 |
| 80 kg (176 lb) | 500 mg · 14.7 | 560 mg · 8.2 | 400 mg · 7.8 | 600 mg · 8.3 |
| 100 kg (220 lb) | 500 mg · 14.7 | 700 mg · 10.2 | 400 mg · 7.8 | 600 mg · 8.3 |
Adult limits. Articaine is not recommended under 4 years of age, and children's maximums for the other agents are covered in the pediatric section below.
What is the induction dose of propofol and ketamine?
Induction is given as a range per kg and titrated to effect, so the second tab shows a low and a high figure rather than a single maximum.
| Drug and patient | Label range | 70 kg example | Strength |
|---|---|---|---|
| Propofol, adult under 65, ASA I or II | 2 to 2.5 mg/kg | 140 to 175 mg | 10 mg/mL |
| Propofol, elderly, debilitated or ASA III or IV | 1 to 1.5 mg/kg | 70 to 105 mg | 10 mg/mL |
| Propofol, age 3 to 16, ASA I or II | 2.5 to 3.5 mg/kg | Weight based | 10 mg/mL |
| Ketamine, intravenous | 1 to 4.5 mg/kg (2 mg/kg average) | 70 to 315 mg | 10 or 50 mg/mL undiluted |
| Ketamine, intramuscular | 6.5 to 13 mg/kg | 455 to 910 mg | 100 mg/mL may be given undiluted |
The 100 mg/mL ketamine strength must be diluted with an equal volume before it goes in a vein. Premedication with an opioid or a benzodiazepine can lower the propofol dose needed.
How do you dose local anesthetic for a child?
Labels give few fixed pediatric maximums. Most point to Clark's rule: the child's weight in lb ÷ 150 × the adult maximum, never above the per kg limit.
| Agent | What the label says for children |
|---|---|
| Lidocaine | For a 5 year old of about 23 kg, roughly 75 to 100 mg (3.3 to 4.4 mg/kg). Under 10, a single tooth rarely needs more than half a dental cartridge, 18 to 20 mg. |
| Articaine | Not recommended under 4 years. Above that, the same 7 mg/kg ceiling as adults. |
| Mepivacaine | Child's weight in lb × 400 mg ÷ 150. |
| Prilocaine | Clark's rule for children under 10 with normal lean body mass; rarely more than half a cartridge (40 mg) under 10. |
| Bupivacaine | Labelled for adults only. |
| Propofol induction | 2.5 to 3.5 mg/kg from age 3 to 16 (ASA I or II); younger children within that range may need the higher end. |
What changes the safe anesthetic dose?
Weight sets the starting figure. These factors from the labels can pull it lower, and none of them push it above the label cap.
| Factor | What it changes | Typical effect |
|---|---|---|
| Epinephrine | Slows absorption from the injection site, so lidocaine and bupivacaine carry higher limits with it. | Lidocaine 4.5 to 7 mg/kg; bupivacaine 175 to 225 mg |
| Age and frailty | Elderly, debilitated and acutely ill patients should get reduced doses. | Propofol drops to 1 to 1.5 mg/kg |
| Liver disease | Amide anesthetics are cleared by the liver. | Consider reduced dosing in moderate to severe impairment |
| Injection site | The labels tie the limit to the expected rate of absorption from where you inject. | Individualise below the cap |
| Concentration | Changes the mL, not the mg. A stronger solution reaches the cap in less volume. | 2% = 20 mg/mL; 4% = 40 mg/mL |
| Dose already given | Every injection in the same sitting counts toward one limit. | Remaining = maximum minus given |
| Physical status | ASA III or IV patients clear propofol more slowly. | Lower induction range |
| Premedication | Opioids and benzodiazepines given first lower the induction need. | Titrate down from the range |
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Book a free demoFrequently asked questions
Short answers on label limits, cartridges, children and what the calculator does not cover.
Book a free demoHow accurate is this anesthesia dose calculator?
The arithmetic is exact and every limit is the maximum printed on the US drug label for that product. Results are rounded down, never up. Brands and formulations can carry different limits, so check the label on the product you are using.
Does this calculator replace clinical decision making?
No. It is a calculation aid for trained clinicians. The final dose belongs to the clinician giving it, checked against the label, the institution's protocol and a second clinician.
What factors affect anesthesia dosing?
Weight first, then whether epinephrine is in the solution, the injection site, age and frailty, liver function and how much has already been given. Labels call for reduced doses in elderly, debilitated and acutely ill patients.
What is the maximum dose of lidocaine with and without epinephrine?
For a healthy adult the label limit is 4.5 mg/kg and no more than 300 mg without epinephrine, and 7 mg/kg and no more than 500 mg with it. A 70 kg adult therefore tops out at 300 mg plain or 490 mg with epinephrine.
How do I use a local anesthetic max dose calculator for dental cartridges?
Pick the agent and the cartridge size, enter the weight, and the calculator divides the remaining mL by 1.7 or 1.8 mL. A 2% cartridge of 1.7 mL holds 34 mg; a 4% articaine cartridge holds 68 mg.
Can it be used for both general and local anesthetics?
Yes. The first tab gives maximum doses for local anesthetics; the second gives the label induction range for propofol and for ketamine by vein or by muscle.
Does it support pediatric or veterinary dosing?
Pediatric, partly: enter an age under 10 to see each label's pediatric wording, and mepivacaine and prilocaine switch to the Clark's rule formula their labels print. Veterinary, no: the limits come from human labels, so animal doses need a veterinary reference.
Should I use actual or ideal body weight?
The labels for these products state their limits per kg or per lb of body weight and do not name ideal or lean weight, so the calculator uses the weight you enter. If your protocol doses an obese patient on ideal or lean weight, enter that figure instead.
What happens if the maximum dose is exceeded?
Blood levels rise with the total dose, and local anesthetic toxicity can affect the brain and heart. The calculator flags a weight based figure above the label total, caps it, and shows a warning once the mg already given reaches the limit.
Does it check drug interactions?
No. Interactions, allergies and conditions such as methemoglobinemia risk with prilocaine are outside what a weight based sum can check, so review them separately.
Why does bupivacaine show a total instead of a per kg limit?
Its current US label gives total doses only: up to 175 mg plain or 225 mg with epinephrine per dose, 90 mg per dental sitting, and no more than 400 mg in 24 hours.
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Published by ServiceAgent, the AI front office for service businesses. This anesthesia dose calculator is a calculation aid for trained clinicians, not medical advice, and it does not replace clinical judgment. Limits shown are the maximums on US drug labels for the products named and can differ between brands and formulations. Doses must be individualised to the patient, the procedure and the injection site, and reduced where a label or your protocol calls for it. Check each dose with the current product label, local protocol and a colleague before it is drawn up.