Clinical Tools

Dermatology dosing calculators

Quick bedside dosing aids. For licensed clinician use. Always confirm against current prescribing guidelines.

Kenalog Dilution Isotretinoin (Accutane)Ivermectin: Scabies Syringe Key

Kenalog dilution calculator

How much Kenalog and bacteriostatic NaCl to reach a target intralesional concentration.

Kenalog stock (mg/mL)

Target concentration (mg/mL)

Volume needed (mL)

Mixing recipe

0.1 mL

Kenalog 10 mg/mL

0.3 mL

Bacteriostatic NaCl

0.4 mL

at 2.5 mg/mL

Dilution ratio

1 : 3

Kenalog : NaCl

Fold dilution

4×

10 → 2.5 mg/mL

Triamcinolone total

1 mg

in 0.4 mL

For licensed clinician use. Dilution math only (C₁V₁ = C₂V₂). It does not replace clinical judgment. Verify concentrations, use bacteriostatic 0.9% sodium chloride, maintain aseptic technique, and confirm the intended intralesional dose and injection site. Small volumes are sensitive to measurement error.

Isotretinoin cumulative-dose calculator

Estimates the cumulative dose target and time to complete a course.

Patient weight (lbs)

Titration schedule

Month 1 (mg/day)

Month 2 (mg/day)

Month 3+ (mg/day)

Patient has already started treatment

Enter a patient weight to calculate.

For licensed clinician use. Estimates only, provided as a dosing aid. They do not replace clinical judgment. Verify all dosing against current isotretinoin prescribing information and confirm iPLEDGE requirements. Isotretinoin is a potent teratogen; pregnancy must be excluded and prevented. Cumulative-dose targets and titration vary by patient, indication, and tolerability.

Ivermectin dosing calculator for scabies

Weight-based dose at 200 mcg/kg for standard scabies treatment.

Patient weight (lbs)

For licensed clinician use. Estimates only. They do not replace clinical judgment. Verify against current prescribing information. Oral ivermectin for scabies is generally avoided in pregnancy and is not for use in patients under 30 kg. Tablet counts are rounded from the 200 mcg/kg calculation.

Syringe key

A visual guide to syringe sizes and how to read their measurements.

Know your graduations

Every syringe is divided a little differently. The lowest dose you can measure depends on how many lines fit between the big numbers: divide the capacity by the number of divisions and you have your smallest reliable measurement.

Tuberculin (1 mL)

smallest mark: 0.01 mL

Intradermal tests (PPD/allergy) and very small subcutaneous doses.

milliliters (mL)

Standard (3 mL)

smallest mark: 0.1 mL

The everyday workhorse: most subcutaneous and IM injections.

milliliters (mL)

Medium (5 mL)

smallest mark: 0.2 mL

Larger IM doses that won't fit comfortably in a 3 mL.

milliliters (mL)

Large (10 mL)

smallest mark: 0.2 mL

Drawing up, reconstituting, and flushing lines.

milliliters (mL)

Insulin (U-100, 1 mL)

smallest mark: 1–2 units

Insulin ONLY. Calibrated in units, never in mL.

units

Find the big marks first

Locate the labeled milliliter (or unit) lines, then count the small lines between them to know the value of each division.

Read at the ring

Line your dose up with the front (top) edge of the rubber plunger tip, not the raised dome or the very bottom.

Match the syringe to the volume

Pick the smallest syringe that fits the dose. A snug fit means more graduation lines and a more accurate measurement.

TB is not insulin

Tuberculin and insulin syringes look alike but are calibrated completely differently. Insulin is measured in units. Never draw up other medications in it.

Safety: always double-check the concentration and the ordered dose, use aseptic technique, and dispose of every needle in an approved sharps container immediately after use. This page is an educational reference, not a substitute for institutional policy or clinical training.