Body mass index
BMI = weight (kg) ÷ height (m)²
Categories follow the standard adult WHO cut-offs.
Body metrics
BMI, body surface area and weight descriptors
Sex (for weight formulas)
Calculated result
BMI—
BSA (Mosteller)—
BSA (Du Bois)—
Ideal body weight—
Adjusted body weight—
Lean body weight (Boer)—
Renal function
Cockcroft–Gault clearance and CKD-EPI 2021 eGFR
Creatinine unit
Sex
Calculated result
Cockcroft–Gault CrCl—
eGFR (CKD-EPI 2021)—
KDIGO category—
CrCl normalised to BSA· enter body metrics—
Infusion rate
Pump rate from your ordered dose — no medicine database, you supply the numbers
Dose interval
Weight based
Calculated result
Pump rate—
Concentration—
Amount per hour—
Drip rate & fluids
Gravity drip rate, infusion duration and 4-2-1 maintenance estimate
Drop factor (gtt/mL)
Calculated result
Drip rate—
Infusion duration—
Maintenance fluid—
Maintenance per 24 h—
Formulas and clinical reference
Body surface area
Mosteller = √(height (cm) × weight (kg) ÷ 3600)
Du Bois is shown alongside for comparison.
Ideal / adjusted body weight
IBW = base + 2.3 × (height in inches − 60); ABW = IBW + 0.4 × (actual − IBW)
Base is 50 kg (male) or 45.5 kg (female). Lean body weight uses the Boer equation.
Creatinine clearance
CrCl = ((140 − age) × weight) ÷ (72 × SCr mg/dL), × 0.85 if female
Cockcroft–Gault. Choose the body weight descriptor appropriate to your local protocol.
eGFR
CKD-EPI 2021 creatinine equation (race-free), mL/min/1.73 m²
Staging labels follow KDIGO G1–G5 categories.
Infusion rate
Rate (mL/h) = amount required per hour ÷ concentration (amount per mL)
You supply the dose; this tool stores no product- or medicine-specific dosing data.
Gravity drip rate
drops/min = rate (mL/h) × drop factor (gtt/mL) ÷ 60
Common drop factors: 10, 15, 20 (macro) and 60 gtt/mL (micro).
Maintenance fluids
Holliday–Segar 4-2-1: 4 mL/kg/h (first 10 kg) + 2 (next 10 kg) + 1 (remainder)
An estimate only; adjust for clinical status, losses and local policy.
Decision support for healthcare professionals only. Verify every result against your local protocol before clinical use. This tool contains no medicine-specific dose data on this page and no patient records.