# Medical & Clinical calculators

> Published clinical formulas and scores: eGFR, creatinine clearance, LDL, anion gap, corrected calcium and sodium, A1C, QTc, MELD, CHA₂DS₂-VASc, Wells, fluids, drip rates, unit conversions. Informational only.

21 calculators. HTML index: https://tttkmbb.com/medical · JSON: https://tttkmbb.com/api/v1/calculators?category=medical

- [eGFR Calculator](https://tttkmbb.com/medical/egfr.md): Estimates glomerular filtration rate from serum creatinine, age and sex with the CKD-EPI 2021 race-free creatinine equation, and assigns the KDIGO GFR category (G1–G5). Tool: `calculate_egfr`.
- [Creatinine Clearance Calculator](https://tttkmbb.com/medical/creatinine-clearance.md): Estimates creatinine clearance in mL/min with the Cockcroft-Gault equation from age, weight, sex and serum creatinine, and, when height is given, also reports the values using ideal (Devine) and adjusted body weight. Tool: `calculate_creatinine_clearance`.
- [LDL Cholesterol Calculator](https://tttkmbb.com/medical/ldl-cholesterol.md): Calculates LDL cholesterol from total cholesterol, HDL and triglycerides with the Friedewald equation (mg/dL or mmol/L), plus non-HDL cholesterol and the NCEP LDL category. Tool: `calculate_ldl_cholesterol`.
- [Anion Gap Calculator](https://tttkmbb.com/medical/anion-gap.md): Computes the serum anion gap from sodium, chloride and bicarbonate, optionally including potassium, and the albumin-corrected gap (Figge) for hypoalbuminaemia. Tool: `calculate_anion_gap`.
- [Corrected Calcium Calculator](https://tttkmbb.com/medical/corrected-calcium.md): Adjusts total serum calcium for low or high albumin with the Payne formula, in conventional (mg/dL, g/dL) or SI units (mmol/L, g/L), and reports both unit systems. Tool: `calculate_corrected_calcium`.
- [Corrected Sodium Calculator](https://tttkmbb.com/medical/corrected-sodium.md): Corrects measured serum sodium for the dilutional effect of hyperglycaemia using the Katz 1.6 mmol/L and Hillier 2.4 mmol/L factors per 100 mg/dL of glucose above 100 mg/dL. Tool: `calculate_corrected_sodium`.
- [A1C to Average Glucose Calculator](https://tttkmbb.com/medical/a1c-to-glucose.md): Converts HbA1c (%) to estimated average glucose in mg/dL and mmol/L with the ADAG study equation, or an average glucose back to A1C, and reports the IFCC value in mmol/mol. Tool: `convert_a1c_to_glucose`.
- [QTc Calculator](https://tttkmbb.com/medical/qtc-interval.md): Corrects a measured QT interval for heart rate with the Bazett, Fridericia, Framingham and Hodges formulas and flags prolongation against the sex-specific thresholds (450 ms men, 460 ms women). Tool: `calculate_qtc_interval`.
- [MELD Score Calculator](https://tttkmbb.com/medical/meld-score.md): Computes the Model for End-Stage Liver Disease score from bilirubin, INR and creatinine (with the OPTN bounding and rounding rules) and MELD-Na when sodium is supplied, and reports the observed 3-month mortality band from Wiesner 2003. Tool: `calculate_meld_score`.
- [CHA₂DS₂-VASc Score Calculator](https://tttkmbb.com/medical/cha2ds2-vasc-score.md): Scores stroke risk in non-valvular atrial fibrillation from age, sex, heart failure, hypertension, diabetes, prior stroke/TIA and vascular disease, and reports the adjusted annual stroke rate from the Euro Heart Survey (Lip 2010) plus the sex-free CHA₂DS₂-VA score. Tool: `calculate_cha2ds2_vasc_score`.
- [Wells Score for DVT Calculator](https://tttkmbb.com/medical/wells-score-dvt.md): Sums the Wells clinical criteria for suspected deep vein thrombosis and reports the three-tier (low/moderate/high) and two-tier (unlikely/likely) pretest probability categories. Tool: `calculate_wells_dvt_score`.
- [Parkland Formula Calculator](https://tttkmbb.com/medical/parkland-formula.md): Calculates the first 24-hour crystalloid volume for burn resuscitation from body weight and percent total body surface area burned (4 mL × kg × %TBSA), split into the first 8 hours and the next 16 hours with hourly rates. Tool: `calculate_parkland_fluids`.
- [Maintenance Fluids Calculator](https://tttkmbb.com/medical/maintenance-fluids.md): Calculates maintenance fluid requirements from body weight with the Holliday-Segar method: the hourly 4-2-1 rule and the daily 100-50-20 mL/kg volume, plus the NICE 25–30 mL/kg/day adult range. Tool: `calculate_maintenance_fluids`.
- [Pack-Years Calculator](https://tttkmbb.com/medical/pack-years.md): Converts a smoking history into pack-years (packs per day × years smoked, 20 cigarettes per pack) and notes the USPSTF lung-cancer screening threshold of 20 pack-years. Tool: `calculate_pack_years`.
- [IV Drip Rate Calculator](https://tttkmbb.com/medical/iv-drip-rate.md): Converts an infusion volume and duration into a gravity drip rate in drops per minute for a given tubing drop factor, and the equivalent pump rate in mL per hour. Tool: `calculate_iv_drip_rate`.
- [Oxygen Tank Duration Calculator](https://tttkmbb.com/medical/oxygen-tank-duration.md): Estimates how long a compressed-gas oxygen cylinder will last from its gauge pressure, size-specific conversion factor (litres per psi), a safe residual pressure and the flow rate. Tool: `estimate_oxygen_tank_duration`.
- [Glucose Unit Converter](https://tttkmbb.com/medical/glucose-unit-conversion.md): Converts blood glucose between mg/dL (US) and mmol/L (SI) using the molar mass of glucose (1 mmol/L = 18.016 mg/dL, i.e. mg/dL × 0.0555). Tool: `convert_glucose_units`.
- [Cholesterol Unit Converter](https://tttkmbb.com/medical/cholesterol-unit-conversion.md): Converts total, HDL, LDL or non-HDL cholesterol (factor 0.02586) and triglycerides (factor 0.01129) between mg/dL and mmol/L. Tool: `convert_cholesterol_units`.
- [Vitamin IU Converter](https://tttkmbb.com/medical/vitamin-iu-conversion.md): Converts international units to mass and back for vitamin D (1 µg = 40 IU), vitamin A as retinol (1 IU = 0.3 µg) and vitamin E as natural d-alpha-tocopherol (1 IU = 0.67 mg) or synthetic dl-alpha-tocopherol (1 IU = 0.9 mg by mass, 0.45 mg alpha-tocopherol equivalents for RDA purposes). Tool: `convert_vitamin_iu`.
- [Adjusted Body Weight Calculator](https://tttkmbb.com/medical/adjusted-body-weight.md): Computes ideal body weight (Devine) and adjusted body weight (IBW + 0.4 × (actual − IBW)) used for drug dosing and creatinine clearance in people whose weight exceeds 120% of ideal. Tool: `calculate_adjusted_body_weight`.
- [Dose by Weight Calculator](https://tttkmbb.com/medical/dose-by-weight.md): Converts a weight-based dose (mg/kg per dose or per day) into milligrams per administration and per day, the volume per administration for a given concentration, and applies an optional maximum single dose. Tool: `calculate_dose_by_weight`.