Colloid Osmotic Pressure Calculator
Determines the pressure induced by proteins in blood plasma that tends to pull fluid into the capillaries.
Refer to the text below the tool for more information on this type of pressure.
Colloid osmotic pressure is also called oncotic pressure and in plasma is about 0.5% of the total osmotic pressure. The large majority of COP in capillaries (appx 80%) of the total oncotic pressure exerted by blood plasma on interstitial fluid is generated by albumin.
Plasma colloid osmotic pressure is an important determinant in the appearance of edema and in critically ill patients, a reliable predictor of survival.
Colloid Osmotic Pressure (COP) = (Globulin in g/dL x 1.4) + (Albumin in g/dL x 5.5)
| Parameter | Normal Low | Normal High |
| Globulin | 2 g/dL (20 g/L) | 3.5 g/dL (35 g/L) |
| Albumin | 3.4 g/dL (34 g/L) | 5.4 g/dL (54 g/L) |
| Colloid Osmotic Pressure (COP) | 23 mmHg | 29 mmHg |
Send Us Your Feedback
Steps on how to print your input & results:
1. Fill in the calculator/tool with your values and/or your answer choices and press Calculate.
2. Then you can click on the Print button to open a PDF in a separate window with the inputs and results. You can further save the PDF or print it.
Please note that once you have closed the PDF you need to click on the Calculate button before you try opening it again, otherwise the input and/or results may not appear in the pdf.
Colloid Osmotic Pressure Explained
In normal plasma, the proteins are the major colloids present and as the colloids are solutes, they contribute to the total osmotic pressure of the solution. Colloid osmotic pressure is also called oncotic pressure and in plasma is about 0.5% of the total osmotic pressure.
The large majority of COP in capillaries (appx 80%) of the total oncotic pressure exerted by blood plasma on interstitial fluid is generated by albumin.
Colloid Osmotic Pressure = (Globulin in g/dL x 1.4) + (Albumin in g/dL x 5.5)
COP has the opposing effect of hydrostatic blood pressure (drawing molecules into the interstitial spaces) and interstitial colloidal osmotic pressure.
In a steady state the measured colloid osmotic pressure replicates the value computed from serum proteins and in healthy individuals it averages 25.4 mmHg. It tends to decrease with age and is lower in females and during extended bed rest.
Reference ranges
| Parameter | Normal Low | Normal High |
| Globulin | 2 g/dL (20 g/L) | 3.5 g/dL (35 g/L) |
| Albumin | 3.4 g/dL (34 g/L) | 5.4 g/dL (54 g/L) |
| Colloid Osmotic Pressure (COP) | 23 mmHg | 29 mmHg |
Plasma colloid osmotic pressure is an important determinant in the appearance of edema and in critically ill patients, a reliable predictor of survival. In conditions where plasma proteins are reduced, for example proteinuria, there will be a reduction in oncotic pressure and an increase in filtration across the capillary, resulting in edema.
References
Ingerslev P, Larsen OA, Lassen NA. Measurement of the colloid osmotic pressure in serum with Tybjaerg Hansen's osmometer. Scand J Clin Lab Invest. 1966; 18(4):431–436.
Webber CE, Garnett ES. The relationship between colloid osmotic pressure and plasma proteins during and after cardiopulmonary bypass. J Thorac Cardiovasc Surg. 1973; 65(2):234–237.
Specialty: Hematology
Abbreviation: COP
Article By: Denise Nedea
Published On: June 15, 2020 · 12:00 AM
Last Checked: June 15, 2020
Next Review: June 15, 2025