Health

Read a heart rate off an ECG strip: the 300 and 1500 box rules, the six-second complex count for irregular rhythms, or a measured RR interval.

Estimates the calories burned in a session from your average heart rate, sex, age and weight, using the published Keytel equations rather than a MET table.

Work the PSI or PORT score for community-acquired pneumonia: twenty weighted items, the risk class I to V and the cohort mortality behind it.

Predicted peak flow from height, age and sex using the Nunn and Gregg 1989 equations, plus the percentage of personal best and the green, yellow and red bands.

How much of a dose is left after a given time at a stated half-life, and how far repeated dosing builds up before it levels off.

Score the ten activities of daily living on the Barthel Index, from feeding to stairs, and get the total out of 100 with the dependence band it falls in.

Estimate free and bioavailable testosterone from total testosterone, SHBG and albumin using the Vermeulen equation, with both fractions and the constants shown.

Estimates the extra daily energy breastfeeding costs, from the baby's age and how much of the feeding is breast milk, or from a milk volume you have measured.

Works out the ankle-brachial index for each leg from four ankle pressures and two arm pressures, with the published bands and the calcified-vessel caveat.

Turns a daily step count into a calorie deficit and a range of likely weight change, showing both the 3,500 rule figure and the smaller one that allows for adaptation.

Turns a Galloway run-walk ratio and its two paces into one overall pace and a finish time, and solves backwards for the running pace a target needs.

Works out the urine protein-to-creatinine ratio in mg/mg, mg/g and mg/mmol, grades it against the KDIGO bands and estimates the 24-hour protein.

Adult maintenance IV fluid volume by the Holliday-Segar rule, showing both the 4-2-1 hourly rate and the 100-50-20 daily volume it was rounded from.

Pace from a treadmill belt speed, plus the incline adjustment: the flat belt speed and the outdoor pace that cost the same oxygen, from the ACSM equations.

Billable units from treatment minutes under the Medicare 8-minute rule, and the productivity percentage those units give against a worked day.

Corrects serum sodium for hyperglycaemia by both the Katz 1.6 and the Hillier 2.4 factors, shows how far apart they are, and checks a rate of change.

Estimates total-body skeletal muscle mass from Lee's MRI-validated anthropometric equations, with the skeletal muscle index and the real error band.

Works out the MELD 3.0 liver disease severity score, and the older MELD-Na, applying the published flooring, capping and dialysis rules to each lab value.

Works out the glucose ketone index from a blood glucose and a blood ketone reading, converts mg/dL to mmol/L, and names the band the result falls in.

Scores a decathlon from the World Athletics tables: all ten marks, one event on its own, or the mark a points target needs.

Calories eaten minus calories burned, with the resting metabolism that sits inside every exercise figure taken out so the day is not counted twice.

Works out the published rule of thumb for prepared formula, about 2 to 2.5 fl oz per pound of body weight a day, split across feeds and capped at around 32 oz.

Works out smoking pack-years from cigarettes or packs a day and the years smoked, and adds up several periods at different rates into one total.

Estimate how many days a flight will take to shake off from the time shift and its direction, and get a day by day light exposure schedule.

Turns a CGM mean glucose into a Glucose Management Indicator and sets it beside a laboratory A1C, so the gap between the two becomes the number you read.

Transposes a prescription between plus and minus cylinder, reads out both eyes with the near power and spherical equivalent, and adds two lenses at different axes.

Glucocorticoid equivalency reference: equal anti-inflammatory doses of prednisone, methylprednisolone, dexamethasone, hydrocortisone and the rest, side by side.

Places one systolic and diastolic reading in its 2017 ACC/AHA category, applying the higher-category rule, and gives the pulse pressure and mean arterial pressure.

Adds up the fourteen Berg Balance Scale items out of 56 and places the total in its published fall-risk band, with the tasks losing the most points named.

Averages a set of blood pressure readings and gives the ACC/AHA category of the average, the spread, and the gap between the first reading and the rest.

Works out a vertical jump from hang time or from standing reach and touch height, then estimates jump power with the named Sayers and Lewis formulas.

Works out the diluent to add to a powdered vial for a concentration you want, and the volume that carries a stated amount once it is mixed.

Divides PaO2 by FiO2, takes mmHg or kPa and per cent or fraction, applies the altitude correction and reads off the Berlin severity band for ARDS.

Which ABO and Rh blood types a child can have, from the parents' types, plus exact Mendelian percentages when the parents' genotypes are known.

Estimates how long until blood alcohol returns to zero after drinking, from drinks, body weight and time elapsed, with the range around that estimate.

Converts a height between feet and inches, centimetres and metres, and places a child or teenager from 2 to 20 on the CDC stature-for-age percentile chart.

Scores the five Bishop criteria - dilation, effacement, station, consistency and position - with the modifiers, and shows the band the total falls in.

Works out systemic vascular resistance from mean arterial pressure, central venous pressure and cardiac output, with the indexed figure and the pulmonary variant.

Turns the watts or kilojoules an indoor bike reports into calories burned, with the resting share separated out and the implied MET shown.

Scores the original 1977 Goldman index across its nine weighted criteria and reports the class, alongside what that class actually did in the cohort the index was derived on.

Free water deficit in hypernatraemia from total body water and the measured sodium, with the volume the usual 24-hour correction-rate limit allows and the rate that implies.

Cardiac output and cardiac index by the Fick principle, from oxygen consumption, haemoglobin and the arterial and mixed venous saturations.

Corrected or adjusted age for a baby born early, from the due date or the gestational age at birth, with the chronological and postmenstrual ages too.

Converts a lens power between two vertex distances, such as a spectacle prescription to the corneal plane, meridian by meridian.

Works out the days supply from the quantity and the dose, the date the supply runs out, and the earliest date a pharmacy will usually refill it.

Works out HOMA-IR from a fasting glucose and a fasting insulin in either unit system, with HOMA-B and QUICKI from the same pair.

Turns a length and a girth measurement into the nominal width printed on a condom box, plus the length range to look for and how the figure is worked out.

Estimates a child's adult height from both parents using the mid-parental method, and gives the 10 cm range either side that the estimate is really good to.