Calculator inputs
Example data table
| Case | Weight | Ordered dose | Frequency | Concentration | Expected single dose | Volume |
|---|---|---|---|---|---|---|
| Pediatric suspension example | 18 kg | 10 mg/kg | 2 doses/day | 50 mg/mL | 180 mg | 3.6 mL |
| Adult oral tablet example | 70 kg | 7.5 mg/kg | 1 dose/day | 125 mg/tablet | 525 mg | 4.2 tablets |
| Single-dose cap example | 62 kg | 12 mg/kg | 2 doses/day | 100 mg/mL | 744 mg raw, capped as entered | Depends on cap |
| Daily cap example | 95 kg | 8 mg/kg | 3 doses/day | 80 mg/mL | Adjusted by daily limit | Depends on limit |
Formula used
- Weight in kilograms = pounds × 0.45359237
- Raw single dose (mg) = weight (kg) × ordered dose (mg/kg)
- Final single dose (mg) = raw dose after single-dose and daily-dose limits
- Daily total (mg/day) = final single dose × doses per day
- Course total (mg) = daily total × therapy days
- Volume per dose (mL) = final single dose ÷ concentration (mg/mL)
- Tablets per dose = final single dose ÷ tablet strength (mg/tablet)
- Rounded amounts use the nearest selected syringe or tablet increment
How to use this calculator
- Enter the patient weight and choose kg or lb.
- Enter the ordered dose in mg per kg.
- Add liquid concentration or tablet strength when needed.
- Set dosing frequency and total therapy days.
- Enter maximum single or daily limits if your protocol uses them.
- Choose rounding rules for liquids and tablet fractions.
- Press the calculate button to show results above the form.
- Review the warnings, graph, and downloadable summary before use.
Frequently asked questions
1) What does mg per kg mean?
It means the ordered amount depends on body weight. The dose is calculated by multiplying weight in kilograms by the prescribed mg/kg ratio.
2) Can I enter weight in pounds?
Yes. The calculator converts pounds to kilograms automatically using the standard conversion factor before applying the mg/kg formula.
3) Why would I use a maximum single dose?
Some protocols cap the amount given at one time, even when a weight-based formula produces a higher value. Entering that cap helps compare raw and adjusted results.
4) Why would I use a maximum daily dose?
A daily limit restricts the total amount allowed across all administrations in one day. The calculator divides that limit across entered doses per day.
5) How is liquid volume calculated?
The calculator divides the final single dose in milligrams by the product concentration in mg/mL. It also shows a rounded volume for practical measurement.
6) How are tablets calculated?
The tool divides the final single dose by the tablet strength. It then shows a rounded tablet count based on the fraction you selected.
7) Does this calculator replace clinical judgment?
No. It supports checking arithmetic, conversions, and documentation. Drug-specific references, patient factors, and local policy still need independent verification.
8) Can I download the result?
Yes. After calculation, use the CSV button for spreadsheet-friendly output or the PDF button for a formatted summary you can save or share.