Nursing specialty hub
Emergency nursing calculators & guides
A fast-access hub for existing MedMaths calculators that may be useful during emergency nursing calculation workflows and revision.
Start with the task
What do you need to work out right now?
Pick the question that matches the medication order, IV order or laboratory result in front of you.
I have an ordered mg dose. How many mL do I give?
Enter the prescribed dose and the strength shown on the medicine label.
The order is written in mg/kg. How many mL per dose?
Use the weight-based order, patient weight and liquid medicine strength.
I have a volume and time. What mL/hr do I set?
Calculate the pump rate directly without entering a giving-set drop factor.
I need an anion gap now
Enter the reported electrolytes and calculate the arithmetic result directly.
Emergency calculator toolkit
Get to the calculation without hunting through the page
The same MedMaths calculator pages are grouped here by the problem you are trying to solve.
Medication doses
Convert the order into the amount to give
Fast access to fixed-dose and weight-based liquid medication calculations.
IV + fluids
Set the rate or work out the time
Use the order in front of you to calculate pump rate, gravity drip rate or infusion duration.
IV Infusion Rate Calculator
Use this when
Use when the order says a volume over a time and you need the mL/hr pump rate. No drop factor is required.
Open calculatorIV Drip Rate Calculator
Use this when
Use when the giving-set drop factor is known and the order provides either mL/hr or total volume and time.
Open calculatorIV Infusion Time Calculator
Use this when
Use when you know the volume to infuse and mL/hr rate and need to know how long it will take or when it will finish.
Open calculatorMetabolic + lab
Calculate the lab arithmetic
Get the number quickly, then interpret it in the clinical context rather than treating the calculator as a diagnosis.
Anion Gap Calculator
Use this when
Use when you need the potassium-free anion-gap arithmetic, with optional albumin adjustment, for comparison with the reporting laboratory reference interval.
Open calculatorSerum Osmolality Calculator
Use this when
Use when you need calculated serum osmolality or, with a measured value, the numeric measured-minus-calculated osmol gap.
Open calculatorCorrected Sodium Calculator
Use this when
Use when a current source asks for a Katz or Hillier hyperglycaemia-adjusted sodium estimate from measured sodium and glucose.
Open calculatorPaediatric quick access
Weight-based paediatric calculations
Keep the documented patient weight central when the emergency calculation is weight based.
mg/kg to mL Dose Calculator
Use this when
Use when a liquid medicine order is written in mg/kg per dose or mg/kg/day and weight is documented in kg or lb.
Open calculatorPaediatric Maintenance Fluids Calculator
Use this when
Use when estimating daily or hourly maintenance fluid requirements for a child. Does not account for deficit, ongoing losses or clinical status.
Open calculatorBrowse by calculation type
Calculation topics used in Emergency
These topic hubs group the same calculators by calculation type. Use them when you want to move from this specialty view into the wider MedMaths calculation pathway.
Calculation topic
Dose Calculations
Start with the medication order and label: find mL from mg, mg/kg, or units without pre-calculating the answer first.
Open topic hubCalculation topic
IV Fluids & Infusions
Choose by the answer you need: pump rate in mL/hr, gravity drops/min, infusion duration, or a check of an existing drip.
Open topic hubCalculation topic
Lab Calculators & Corrections
Laboratory calculation tools for corrected calcium, corrected sodium, anion gap, serum osmolality and osmol gap.
Open topic hubCalculation topic
Paediatric Nursing
Paediatric nursing calculators and guides for weight-based medication maths, maintenance fluids, tablet dosing and BSA.
Open topic hubLearning
Related MedMaths guides
IV Volume, Time and Rate Explained
Understand how IV volume, time and mL/hr fit together, why the same formula can solve for rate, volume or time, and how to handle minutes, remaining volume and common unit mistakes.
How to interpret the anion gap
Interpret the anion gap after calculation: local reference interval, albumin, GOLDMARK, DKA limitations, normal-gap acidosis and low or negative gaps.
Calculated Serum Osmolality and Osmol Gap Explained
Understand directly measured vs calculated serum osmolality, effective osmolality/tonicity, what the osmol gap represents, why formulas and ethanol coefficients change the result, and why the gap must be interpreted as a clue rather than a diagnosis.
Paediatric maintenance fluids explained: 4-2-1 vs 100-50-20
100-50-20 is the Holliday-Segar daily maintenance method; 4-2-1 is a rounded hourly shortcut based on the same weight bands. This guide explains the relationship, why the totals can differ, and the clinical limits of full maintenance.
Use the calculator guidance for each clinical situation
Specialty grouping is designed to help you find tools faster. Always follow the guidance on the individual calculator page, medication references, local policy, and clinical review requirements.