BMI (Body Mass Index)

BMI = weight (kg) / height (m)²

Body Surface Area

BSA (m²) = sqrt[(height(cm) x weight(kg)) / 3600]

Ideal Body Weight

Male: 50 + 2.3 x (height in inches - 60)
Female: 45.5 + 2.3 x (height in inches - 60)

Basal Metabolic Rate

Male: 10W + 6.25H - 5A + 5
Female: 10W + 6.25H - 5A - 161

Adjusted Body Weight

AdjBW = IBW + 0.4 x (Actual Weight - IBW)

Estimated Calorie Requirement (TDEE)

TDEE = BMR (Mifflin-St Jeor) x Activity Factor

Waist-to-Height Ratio

WHtR = Waist circumference / Height (same units)

Waist-to-Hip Ratio

WHR = Waist circumference / Hip circumference (same units)

Creatinine Clearance (Cockcroft-Gault)

CrCl = [(140 - age) x weight(kg)] / (72 x Scr(mg/dL)) x (0.85 if female)

eGFR (CKD-EPI 2021)

eGFR = 142 x min(Scr/κ,1)^α x max(Scr/κ,1)^-1.200 x 0.9938^Age x (1.012 if female)

BUN/Creatinine Ratio

BUN/Cr ratio = BUN (mg/dL) / Creatinine (mg/dL)

eGFR (MDRD)

eGFR = 175 x Scr^-1.154 x Age^-0.203 x (0.742 if female)

Fractional Excretion of Sodium

FeNa (%) = (Urine Na x Plasma Cr) / (Plasma Na x Urine Cr) x 100

Fractional Excretion of Urea

FeUrea (%) = (Urine Urea x Plasma Cr) / (Plasma Urea x Urine Cr) x 100

LDL Cholesterol (Friedewald)

LDL = TC - HDL - TG/5 (mg/dL) or TC - HDL - TG/2.2 (mmol/L)

Non-HDL Cholesterol

Non-HDL = TC - HDL

VLDL Estimation

VLDL = TG / 5 (mg/dL)

Anion Gap

AG = Na - (Cl + HCO3); Corrected AG = AG + 2.5 x (4 - albumin[g/dL])

Corrected Calcium

Corrected Ca (mg/dL) = Measured Ca + 0.8 x (4 - Albumin[g/dL])

Total Cholesterol/HDL Ratio

TC/HDL ratio = Total Cholesterol / HDL

Calcium-Phosphate Product

Ca x PO4 product (mg²/dL²) = Calcium (mg/dL) x Phosphate (mg/dL)

LDL/HDL Ratio

LDL/HDL ratio = LDL / HDL

Delta Gap / Delta Ratio

Delta Gap = AG - 12
Delta Ratio = Delta Gap / (24 - HCO3)

Estimated Serum Osmolality

Osm (mOsm/kg) = 2 x Na + Glucose/18 + BUN/2.8

HbA1c ↔ Estimated Average Glucose

eAG (mg/dL) = 28.7 x HbA1c(%) - 46.7

Corrected Sodium for Hyperglycemia

Corrected Na = measured Na + correction factor × ((glucose − 100) / 100)

Urea ↔ BUN Conversion

Albumin-Corrected Anion Gap

Corrected AG = AG + 2.5 × (4.0 − albumin[g/dL])

Creatinine Unit Conversion

Red Cell Indices

MCV = (Hct × 10) / RBC; MCH = (Hgb × 10) / RBC; MCHC = (Hgb / Hct) × 100

Absolute Cell Count

Absolute count = WBC(x10⁹/L) x (differential % / 100)

Corrected WBC Count

Corrected WBC = (Uncorrected WBC x 100) / (100 + nRBC per 100 WBC)

Hematocrit Estimation

Hct (%) ≈ Hgb (g/dL) x 3

International Normalized Ratio

INR = (PT / mean normal PT)^ISI

Platelet Corrected Count Increment

CCI = platelet increment (/µL) × BSA (m²) ÷ platelet dose (×10¹¹)

Estimated Blood Volume

International Prognostic Index

Reticulocyte Production Index

RPI = reticulocyte % × (patient Hct / reference Hct) ÷ maturation factor

aPTT Ratio

aPTT ratio = patient aPTT ÷ control aPTT

Estimated RBC Transfusion Volume

RBC volume ≈ EBV × (target Hct − current Hct) ÷ product Hct

Revised International Prognostic Index

CFU/mL Estimation

CFU/mL = (colonies counted / volume plated[mL]) x dilution factor

Dilution Factor

Dilution factor = final volume / initial (aliquot) volume

Concentration After Dilution

C2 = C1 / dilution factor

Serial Dilution Total Factor

Total dilution factor = factor₁ × factor₂ × ... × factorₙ

Microbiology Concentration After Dilution

Final concentration = initial concentration ÷ dilution factor

Pooled CFU/mL Estimation

CFU/mL = total colonies ÷ total plated volume × dilution factor

Molarity Calculator

Molarity (M) = mass (g) / [molecular weight (g/mol) x volume (L)]

Normality Calculator

Normality (N) = mass (g) / [equivalent weight (g/eq) x volume (L)]

C1V1 = C2V2 Dilution

C1 × V1 = C2 × V2

Percent Solution Preparation

% w/v = g per 100 mL; % v/v = mL per 100 mL; % w/w = g per 100 g

Molar Solution Preparation

Mass (g) = target molarity × molecular weight × final volume (L)

Reagent Dilution & Solvent Volume

V1 = C2V2/C1; solvent = V2 − V1

Beer–Lambert Law

A = εlc

Absorbance ↔ Transmittance

A = −log10(T), T = 10^(−A), %T = 100T

Spectrophotometry Standard Curve

y = mx + b; x = (y − b)/m

Spectrophotometry Dilution-Corrected Concentration

Original concentration = [(A − b)/m] × dilution factor

Wavelength ↔ Frequency

f = c / λ

Photon Energy from Wavelength

E = hc / λ

Wavelength ↔ Wavenumber

ṽ (cm⁻¹) = 10⁷ / λ(nm)

Blank-Corrected Absorbance

A(corrected) = A(sample) − A(blank)

Spectrophotometry Replicate Statistics

Mean = Σx/n; SD = sample standard deviation; CV% = SD/Mean × 100

Spectrophotometry Calibration Regression

y = mx + b; R² = 1 − SSres/SStot; x = (y − b)/m

Photometric Linearity Check

Deviation (%) = (Observed − Expected) / Expected × 100

Weight-Based Dose (mg/kg)

Dose (mg) = prescribed dose (mg/kg) × weight (kg)

Oral Liquid Dose Volume

Volume (mL) = required dose (mg) ÷ concentration (mg/mL)

Tablet/Capsule Dose Count

Units = required dose ÷ strength per unit

Dose Volume Rounding

Rounded volume = exact volume adjusted to the selected measuring increment

Weight-Based Daily Dose (mg/kg/day)

Daily dose (mg/day) = prescribed dose (mg/kg/day) × weight (kg)

Body Surface Area Dose (mg/m²)

Dose (mg) = prescribed dose (mg/m²) × BSA (m²)

Dose per Administration

Dose per administration = total daily dose ÷ administrations per day

Dose to Volume

Volume (mL) = required dose (mg) ÷ concentration (mg/mL)

Drug Concentration

Concentration (mg/mL) = drug amount (mg) ÷ final volume (mL)

Infusion Rate

Rate (mL/hr) = volume (mL) ÷ time (hr)

IV Drops per Minute

Drops/min = volume(mL) × drop factor(gtt/mL) ÷ time(min)

Maximum Dose Check

Final dose = min(calculated dose, specified maximum)

Artesunate to Severe Malaria

WHO dose: 3 mg/kg per dose for children <20 kg; 2.4 mg/kg per dose for patients ≥20 kg

Artemether–Lumefantrine to Uncomplicated Malaria

Weight band  to  tablets per dose; 6 doses at 0, 8, 24, 36, 48 and 60 hours

Artesunate–Amodiaquine to Uncomplicated Malaria

Weight band  to  fixed-dose combination per day for 3 days

Artesunate–Mefloquine to Uncomplicated Malaria

Weight band  to  fixed-dose combination per day for 3 days

Dihydroartemisinin–Piperaquine to Uncomplicated Malaria

Weight band  to  fixed-dose combination once daily for 3 days

Artesunate–Sulfadoxine/Pyrimethamine to Uncomplicated Malaria

Weight band  to  artesunate daily for 3 days + single SP dose on day 1

Artesunate–Pyronaridine to Uncomplicated Malaria

Weight band  to  fixed-dose combination once daily for 3 days

Amoxicillin to Pediatric Dose

Daily dose = 25–50 mg/kg/day × weight; divided into 3 doses/day

Amoxicillin/Clavulanate to Pediatric Dose

Amoxicillin component = 25–50 mg/kg/day × weight; divided 3 times daily

Azithromycin to Pediatric Dose

Dose = 10 mg/kg once daily

Ceftriaxone to Pediatric Dose

General dose = 50 mg/kg/day; meningitis = 100 mg/kg/day

Cephalexin to Pediatric Dose

Daily dose = 50–100 mg/kg/day × weight; divided into 4 doses

Metronidazole to Pediatric Dose

Daily dose = 15–30 mg/kg/day × weight; divided into 2 doses

Cefuroxime to Surgical Prophylaxis

Dose = 50 mg/kg × weight

Ampicillin to Pediatric Dose

Dose = 50 mg/kg per administration

Cefotaxime to Pediatric Dose

Dose = 50 mg/kg per administration

Cloxacillin to Pediatric Dose

Neonates: 25–50 mg/kg/dose q12h; children: 25 mg/kg/dose q6h

Ciprofloxacin to Pediatric Dose

Weight band  to  fixed dose every 12 hours

Gentamicin to Pediatric Dose

Neonates: 5 mg/kg/dose; children: 7.5 mg/kg/dose

Meropenem to Pediatric Dose

Dose = 20 mg/kg per administration every 8 hours

Vancomycin to Pediatric Dose

Dose = 15 mg/kg per administration

Amoxicillin/Clavulanate to Renal Adjustment

GFR >30: usual regimen; GFR 10–30: 250 or 500 mg q12h; GFR <10: 250 or 500 mg q24h

Ciprofloxacin to Renal Adjustment

CrCl >50: q12h; 30–50: q12h; 5–29: q18h; dialysis: q24h after dialysis

Cefotaxime to Renal Adjustment

CrCl ≥20: usual dose; CrCl <20: 50% of usual dose

Cefuroxime Axetil to Renal Adjustment

CrCl ≥30: no adjustment; 10–<30: q24h; <10: q48h; hemodialysis: extra standard dose after dialysis

Meropenem to Renal Adjustment

CrCl >50: usual q8h; 26–50: usual q12h; 10–25: half-dose q12h; <10: half-dose q24h

Vancomycin to AUC24 Target Check

Target AUC24 = 400–600 mg·h/L (assuming MIC = 1 mg/L)

Gentamicin to Peak/Trough Check

Conventional reference: peak 4–6 mcg/mL (adult) or 3–5 mcg/mL (pediatric); trough <2 mcg/mL

WHO 0–59 Days to Sepsis/Pneumonia Regimen

Ampicillin 50 mg/kg/dose + gentamicin 5 or 7.5 mg/kg once daily

WHO 0–59 Days to Meningitis Regimen

Ampicillin 50 mg/kg/dose or cefotaxime 50 mg/kg/dose or ceftriaxone 100 mg/kg + gentamicin

Piperacillin–Tazobactam to Pediatric Dose

Piperacillin dose = 100 mg/kg/dose × weight; IV every 8 hours

Clindamycin to Pediatric Dose

Neonate: 5 mg/kg/dose q8h; child: 10 mg/kg/dose q8h

Cefazolin to Pediatric Dose

Dose = 25 mg/kg/dose IV every 12 hours

Linezolid to Pediatric Dose

Dose = 10 mg/kg/dose IV/ORAL every 8 hours

Doxycycline to Pediatric Dose

Day 1: 2 mg/kg/dose twice daily; then 2 mg/kg once daily; maximum 100 mg/dose and 200 mg/day

Loading Dose

Loading dose = loading dose rate (mg/kg) × weight (kg)

Maintenance Dose

Dose per administration = total daily dose ÷ administrations per day

Infusion Duration

Time (hours) = volume (mL) ÷ rate (mL/hour)

Course Total Dose

Total course dose = dose per administration × administrations per day × treatment days

WHO Pediatric Pneumonia to Regimen Reference

Dose = 40 mg/kg per dose × weight; twice daily

WHO Pediatric Diarrhoea to Zinc Regimen

Zinc = 5 mg elemental zinc once daily; duration = 10–14 days

WHO Pediatric ORS to Plan B Volume

ORS volume = 75 mL/kg × body weight; administer over 4 hours

WHO Pediatric ORS to Ongoing Losses

<2 years: 50–100 mL per loose stool; 2–<10 years: 100–200 mL per loose stool; ≥10 years: as much as wanted

WHO Pediatric Maintenance IV Fluid

4 mL/kg/hour for first 10 kg + 2 mL/kg/hour for next 10 kg + 1 mL/kg/hour for each subsequent kg

Pediatric Fluid Deficit to Assessed Dehydration

Deficit (mL) = weight (kg) × dehydration (%) × 10

Oncology BSA-Based Dose

BSA (m²) = √[(height cm × weight kg) ÷ 3600]; dose (mg) = protocol dose (mg/m²) × BSA

Chemotherapy Dose Intensity

Dose intensity = cumulative dose (mg/m²) ÷ treatment duration (weeks)

Relative Dose Intensity

RDI (%) = delivered dose intensity ÷ planned dose intensity × 100

Chemotherapy Cumulative Dose

Cumulative dose = dose/administration × administrations/cycle × cycles

Chemotherapy Cycle Total

Cycle total = dose/administration × scheduled administrations

Carboplatin Dose to Calvert Formula

Dose (mg) = target AUC × (GFR + 25)

Chemotherapy Dose Cap Check

Final dose = min(calculated dose, protocol maximum)

Oncology Regimen to Patient-Specific Dose

Oncology Haematologic Dose-Modification Assessment

Oncology Renal & Hepatic Dose-Modification Assessment

Oncology Toxicity / Safety Assessment

Chemotherapy Emetogenic Risk Assessment

Febrile Neutropenia Prophylaxis Risk Assessment

Risk band = estimated febrile-neutropenia probability

Oncology Cycle Progress

Remaining cycles = planned cycles − completed cycles; course progress (%) = completed cycles ÷ planned cycles × 100

Oncology Course Completion

Completed exposure = dose/cycle × completed cycles; remaining planned exposure = dose/cycle × remaining cycles

Mean Arterial Pressure

MAP ≈ (SBP + 2 × DBP) ÷ 3

Left Ventricular Ejection Fraction

EF (%) = (EDV − ESV) ÷ EDV × 100

CHA₂DS₂-VASc Score

DAPT Score

QTc Correction

Atherogenic Index of Plasma

AIP = log10(TG / HDL-C)

Pulse Pressure

Pulse pressure = SBP − DBP

Cardiac Index

Cardiac index = cardiac output ÷ BSA

HAS-BLED Bleeding Risk Score

Atrial Fibrillation Ventricular Rate

Rate (bpm) = QRS count × 60 ÷ strip duration (seconds)

HCT-Specific Comorbidity Index

Conditioning / Transplant Day Tracker

Stem Cell Collection Yield

Dose (×10⁶/kg) = CD34 concentration (cells/µL) × product volume (mL) ÷ 1,000,000 ÷ weight (kg) × 1,000

CD34+ Cell Dose

CD34 dose (×10⁶/kg) = total CD34+ cells (×10⁶) ÷ weight (kg)

Neutrophil Engraftment Timing

Donor Chimerism

Donor chimerism (%) = donor signal ÷ total signal × 100

Stem Cell Collection Target

Target CD34+ cells = target dose (×10⁶/kg) × weight (kg)

Viable CD34+ Cell Dose

Viable dose = total CD34+ cells × viability ÷ weight

Engraftment Duration

Elapsed days = engraftment day − transplant day