billycalc

PERC Rule

PERC Rule: calculated with the published clinical method, with result interpretation. A reference tool that does not replace a doctor's advice.

ℹ Reference calculation based on the published method. It does not replace a clinical examination or a doctor's decision.

PERC Rule

Ageyears
Heart ratebpm
SaO₂%
Unilateral leg swelling (1 = yes)
Hemoptysis (1 = yes)
Surgery or trauma within 4 weeks (1 = yes)
Prior PE or DVT (1 = yes)
Estrogen use (1 = yes)
Positive PERC criteria
0
Use only when clinical probability of PE is low (<15%)PERC Rule: calculated with the published clinical method, with result interpretation. A reference tool that does not replace a doctor's advice.
PERC
Negative: no further testing for PE needed

More about: PERC Rule

What it calculates

The “PERC Rule” calculator computes Positive PERC criteria from 8 parameters: age (years), heart rate (bpm), sao₂ (%), unilateral leg swelling (1 = yes), hemoptysis (1 = yes), surgery or trauma within 4 weeks (1 = yes), prior pe or dvt (1 = yes), estrogen use (1 = yes).

Used by professionals and patients to assess health metrics, dosages, and risks.

Example calculation

With parameters Age = 42 years, Heart rate = 88 bpm, SaO₂ = 98 %, Unilateral leg swelling (1 = yes) = 0, Hemoptysis (1 = yes) = 0, Surgery or trauma within 4 weeks (1 = yes) = 0, Prior PE or DVT (1 = yes) = 0, Estrogen use (1 = yes) = 0 the result is 0 (Use only when clinical probability of PE is low (<15%)).

How to use

  1. Enter age, heart rate, sao₂, unilateral leg swelling (1 = yes), hemoptysis (1 = yes), surgery or trauma within 4 weeks (1 = yes), prior pe or dvt (1 = yes) and estrogen use (1 = yes) — each field above is adjustable with a slider.
  2. Positive PERC criteria is calculated automatically as you type.
  3. Check the worked example below to see the formula applied to real numbers.
  4. Copy the result or bookmark this calculator.

Related calculators

FAQ

How is BMI calculated?
BMI = weight (kg) / height (m)². Example: 70 kg / (1.75 m)² = 22.9. The WHO normal range is 18.5–24.9; below that is underweight, 25–29.9 is overweight, and 30+ is obese.
Is BMI accurate for everyone?
No. BMI does not distinguish muscle from fat, so athletes may show a high BMI with low body fat. It is also less reliable for teenagers, pregnant people, older adults, and very tall or short individuals.
What are the BMI categories?
Underweight: below 18.5. Normal: 18.5–24.9. Overweight: 25–29.9. Obese class I: 30–34.9; class II: 35–39.9; class III: 40+.
What is a better measure than BMI?
Body fat percentage, waist-to-height ratio (aim for under 0.5), and waist circumference give a clearer picture of health than BMI alone.

More calculators in this category

Explore related free tools

Croup ScorePediatric ETT SizeBeck Depression InventoryBipolar (MDQ)Eating Disorder (EAT-26)Air Force PTNavy PRTArmy Body FatNavy Body FatMarine PFTUSCG PFTArmy APFT Pushups/Situps/Run