Nursing Calculators & Clinical Tools
Free, nurse-focused calculators for medication math, IV rates, early warning scores, renal function, and fluids โ with transparent formulas, worked examples, and medical review.
About this nursing calculators hub
This hub brings together free nursing dosage calculators, IV drip rate tools, medication math helpers, clinical scoring tools, and renal function calculators in one searchable directory โ part of the broader NurseOnShift medical library. It is built for ward nurses, ICU staff, emergency department / ER and A&E teams, nursing students preparing for the NCLEX practice hub, educators teaching safe med math, and anyone who needs a transparent formula check at the bedside โ not a substitute for pharmacy or prescriber verification.
Use these tools when you need to double-check a D/H ร Q tablet calculation, programme an IV infusion pump rate, run a NEWS2 calculator or GCS calculator during altered mental status, estimate GFR with CKD-EPI 2021 alongside serum creatinine trends, or work through Holliday-Segar pediatric maintenance fluids. Pair high-risk tools with heparin, norepinephrine, and sepsis reference pages in the med library. High-risk infusions, anticoagulation, weight-based pediatric dosing, and renal drug adjustments always require your unit’s validated protocol, independent check, and pharmacy confirmation.
All nursing calculators
40 toolsTablet Dosage Calculator (D/H ร Q)
Convert a prescribed dose to tablets or capsules using Desired รท Have ร Quantity.
Open calculatorWeight-Based Dosage Calculator
Scale mg/kg orders to total daily or per-dose amounts from patient weight.
High-risk: verify pediatric and weight-based orders with pharmacy and your unit protocol โ never rely on a calculator alone.
Open calculatorIV Drip Rate Calculator (gtt/min)
Drops per minute from volume, time, and drop factor (10, 15, 20, or 60 gtt/mL).
Open calculatormcg/kg/min Infusion Rate Calculator
Convert weight-based pressor orders to mL/hr using drug concentration.
High-risk: vasopressor and inotrope infusions require pump validation, double-check, and protocol-specific concentration โ not calculator output alone.
Open calculatorMAP (Mean Arterial Pressure) Calculator
MAP from systolic and diastolic BP with target ranges for sepsis and neuro care.
Open calculatorGlasgow Coma Scale (GCS) Calculator
Eye, verbal, and motor scoring with severity bands for neurological assessment.
Open calculatorNEWS2 Score Calculator
National Early Warning Score 2 from vitals, SpOโ scale, and supplemental oxygen.
Open calculatorGFR Calculator (CKD-EPI 2021)
Estimated glomerular filtration rate using the race-free CKD-EPI 2021 equation.
Renal dosing: eGFR supports context only โ confirm renally cleared drug doses with pharmacy and local renal-dosing guidance.
Open calculatorLiquid Medication Dosage Calculator
mL to administer for oral liquids using D/H ร Q.
Open calculatorIV Flow Rate Calculator (mL/hr)
Convert volume and time to mL/hr for pump programming.
Open calculatorWeight-Based Heparin Drip Calculator
Illustrative bolus and maintenance rates using common nomograms โ always follow your institution’s anticoagulation protocol.
High-risk: heparin requires protocol-specific nomograms, aPTT/anti-Xa monitoring, and pharmacy or prescriber verification.
Open calculatorIV Drop Factor Converter
Switch between mL/hr and gtt/min when tubing drop factors change.
Open calculatorBMI Calculator
Body Mass Index with WHO clinical classification bands.
Open calculatorBSA Calculator (Mosteller)
Body surface area for chemo dosing and indexed hemodynamics.
High-risk: chemotherapy and BSA-based medication dosing must be verified by oncology pharmacy and protocol-specific prescribing systems.
Open calculatorqSOFA Sepsis Screening Calculator
qSOFA may help identify higher-risk patients but must not be used as the sole sepsis screening tool. In hospital settings, follow your local pathway โ NEWS2, MEWS, SIRS, or other approved systems may be preferred.
Open calculatorAnion Gap Calculator
Serum anion gap with optional albumin correction.
Open calculatorCorrected Calcium Calculator
Adjust total calcium for albumin as a screening estimate. Do not use corrected calcium as a substitute for ionized calcium when clinical decisions depend on true calcium status.
Open calculatorCorrected Sodium Calculator
Sodium adjustment for hyperglycemia in DKA/HHS interpretation.
Open calculator24-Hour Fluid Balance Calculator
Sum intake and output for net fluid balance over a shift.
Open calculatorCreatinine Clearance Calculator (Cockcroft-Gault)
Estimate CrCl for medication dosing when protocol requires it.
Renal dosing: CrCl estimates vary in accuracy โ confirm renally adjusted doses with pharmacy; eGFR may be preferred per local guidance.
Open calculatorParkland Burn Formula Calculator
24-hour crystalloid estimate: 4 mL ร kg ร % TBSA.
Burn fluid estimates are starting points only. Titrate to clinical status, urine output, burn-center guidance, and local protocol.
Open calculatorPediatric Maintenance Fluids (Holliday-Segar)
Hourly IV maintenance rate by weight using the 4-2-1 rule.
Pediatric fluids: maintenance estimates do not replace clinical assessment, electrolyte monitoring, or prescriber orders for dehydration or shock.
Open calculatorNaegele Due Date Calculator
Estimated delivery date from LMP with trimester boundaries.
Open calculatorAPGAR Score Calculator
Score appearance, pulse, grimace, activity, and respiration at birth.
Open calculatorIdeal Body Weight (IBW) Calculator
Devine formula IBW from height and sex โ reference for ventilator and dosing context.
Open calculatorAdjusted Body Weight (AdjBW) Calculator
IBW plus fraction of excess weight for obesity dosing protocols.
Open calculatorIV Solution Reconstitution Calculator
Prepare a target concentration using CโVโ = CโVโ proportional math.
High-risk: verify final concentration, diluent, compatibility, route, and expiry against pharmacy guidance or the product monograph.
Open calculatorMEWS Score Calculator
Modified Early Warning Score from vitals and consciousness per local MEWS chart.
Open calculatorSIRS Criteria Calculator
Screen for SIRS using temperature, HR, RR, and WBC โ follow local sepsis pathways.
Open calculatorWells Score for DVT Calculator
Pre-test probability of DVT using the Wells clinical prediction rule.
Open calculatorCURB-65 Score Calculator
Pneumonia severity: confusion, urea, RR, BP, and age โฅ65.
Open calculatorCorrected QT Interval (QTc) Calculator
QTc from QT and heart rate using Bazett or Fridericia formulas.
QTc formula choice matters. Bazett may overcorrect at high heart rates and undercorrect at low heart rates; interpret with ECG context and local guidance.
Open calculatorP/F Ratio (PaOโ/FiOโ) Calculator
P/F ratio for ARDS screening and ICU oxygenation trends.
Open calculatorCardiac Index Calculator
Cardiac index from cardiac output and body surface area.
Open calculatorOsmolal Gap Calculator
Measured minus calculated osmolality for toxic ingestion workups.
Open calculatorFree Water Deficit Calculator
Estimate free water deficit in hypernatremia โ correction rates are protocol-specific.
Open calculatorFENa Calculator (Fractional Excretion of Sodium)
Fractional excretion of sodium for AKI differentiation โ interpret with diuretics and context.
Open calculatorTBSA Calculator (Rule of Nines)
Estimate % TBSA burned before Parkland fluid resuscitation calculations.
Burn fluid estimates are starting points only. Titrate to clinical status, urine output, burn-center guidance, and local protocol.
Open calculatorInsulin Drip Rate Calculator (units/hr)
Convert insulin infusion mL/hr and concentration to units per hour.
High-risk: insulin infusions require local protocol, glucose monitoring, potassium monitoring, and prescriber/pharmacy verification โ never titrate from a calculator alone.
Open calculatorPediatric GCS Calculator
Age-adapted Glasgow Coma Scale for infants and children.
Open calculatorNo calculators match your search.
Try a broader term like “IV”, “dosage”, or “score” โ or clear filters to see all tools.
๐ฉบ Why nurses use these calculators
Clinical math errors remain a leading cause of preventable medication incidents. Whether you are verifying an IV infusion pump rate, scoring a deteriorating patient with sepsis screening and altered mental status, interpreting a basic metabolic panel for electrolyte calculators, or preparing for NCLEX-style dosage questions, transparent arithmetic beats mental math under shift pressure.
Each tool on this hub shows the underlying formula, cites the clinical context, and links to related medication administration, vital signs measurement, and head-to-toe assessment content โ so you can move from calculation to safe practice in one workflow.
Units or mL = (Desired รท Have) ร Quantity
gtt/min = (Volume ร Drop factor) รท Time (min)
MAP โ DBP + (SBP โ DBP) รท 3
Total dose = mg/kg ร Weight (kg)
These calculators support education and independent double-checks. They do not replace pharmacy verification, prescriber orders, institutional protocols, or your professional accountability. For high-risk infusions and weight-based drugs, always follow your unit’s validated pathway. Do not delay urgent escalation, emergency response, medical review, or sepsis treatment while using a calculator.
โ How we build trustworthy tools
NurseOnShift calculators follow the same editorial standards as our medical library: written by practising nurses, medically reviewed, and updated when guidelines change.
Formulas reflect real bedside workflows โ drip checks, escalation scores, and renal dosing contexts nurses encounter on shift.
Content authored by a registered nurse with critical care and respiratory experience; clinical formulas reviewed by a practising emergency physician.
Equations aligned with widely adopted references โ see the clinical references section below โ with full citations on each individual tool page.
No signup, no paywall, no selling your inputs. Clear disclaimers, visible authorship, and links to our editorial policy.
๐ Clinical references used across these tools
Individual calculator pages cite the exact formula-level source for each tool. This hub lists the primary references used across the directory.
Key sources: Royal College of Physicians NEWS2, Surviving Sepsis Campaign 2026, NKF/ASN CKD-EPI 2021, Cockcroft-Gault, and medication safety guidance.