# Systemic Vascular Resistance Calculator (SVR) Compute SVR = 80 × (MAP − CVP) / CO (dyn·s/cm⁵). Normal 800–1440; high in cardiogenic shock and hypertension; low in distributive shock and vasodilators. Derived from Grossman 1991, StatPearls, LITFL, Vincent NEJM 2013, Braunwald. Not medical advice. > Canonical page: https://elysiatools.com/en/tools/systemic-vascular-resistance - **Category:** Health - **Keywords:** systemic vascular resistance, svr, vascular resistance, mean arterial pressure, map, central venous pressure, cvp, afterload, vasoconstriction, vasodilation, shock, sepsis, hemodynamics, cardiology, critical care ## Overview The Systemic Vascular Resistance Calculator computes SVR from mean arterial pressure (MAP), central venous pressure (CVP), and cardiac output (CO): SVR = 80 × (MAP − CVP) / CO, reported in dyn·s/cm⁵. Use the result as a hemodynamic reference, not as medical advice. ## Inputs - **Mean Arterial Pressure MAP (mmHg)** (number): Mean arterial pressure (mmHg). If unknown, MAP = DBP + (SBP − DBP)/3. - **Central Venous Pressure CVP (mmHg)** (number): Central venous pressure (mmHg) from a central line; approximates right atrial pressure. Typical 2–8 mmHg. - **Cardiac Output CO (L/min)** (number): Cardiac output in L/min (from thermodilution, Fick, or echo). - **Decimal Places** (number) ## When to use - Estimate systemic vascular resistance when MAP, CVP, and cardiac output are available. - Review vascular tone and afterload alongside cardiac output in shock or critical-care assessments. - Compare a calculated SVR with the stated normal range of 800–1440 dyn·s/cm⁵. ## How it works - Enter MAP in mmHg, CVP in mmHg, and cardiac output in L/min. - The calculator subtracts CVP from MAP to determine perfusion pressure. - It applies SVR = 80 × (MAP − CVP) / CO. - The result is shown in dyn·s/cm⁵ with a category such as Normal SVR or High SVR; decimal places can be selected. ## Use cases - Critical-care hemodynamic review using pressure and cardiac-output measurements. - Cardiology assessment of afterload and systemic vascular tone. - Teaching and study of shock profiles and the SVR calculation. ## Frequently asked questions ### What is the SVR formula? SVR = 80 × (MAP − CVP) / CO, reported in dyn·s/cm⁵. ### What inputs does the calculator require? It requires MAP in mmHg, CVP in mmHg, and cardiac output in L/min. ### What is the normal SVR range? The stated normal range is 800–1440 dyn·s/cm⁵. ### What if MAP is not available? MAP can be estimated as DBP + (SBP − DBP) / 3, according to the input guidance. ### Is this calculator medical advice? No. It provides a calculation for reference and does not replace clinical assessment. ## Related tools - [Extended BMR Calculator (Mifflin / Schofield Multi-Formula Comparison)](https://elysiatools.com/en/tools/basal-metabolic-rate-ext): Compare Mifflin-St Jeor, original and revised Harris-Benedict, Schofield (FAO/WHO/UNU), and Katch-McArdle BMR equations side by side with mean and spread in kcal/day. Not medical advice. - [Cell Confluency Estimator (Microscopy Grid Method)](https://elysiatools.com/en/tools/confluency-estimator): Estimate adherent-cell confluency with the grid-count method: confluency% = occupied/total squares × 100 per field, with multi-field mean ± SD and optional time-to-target from the doubling time. - [Free Water Clearance Calculator](https://elysiatools.com/en/tools/free-water-clearance): Calculate solute-free water clearance (C_H₂O) and electrolyte-free water clearance (eC_H₂O) to differentiate hypo-/hypernatremia. Classic: C_H₂O = V·(1 − U_osm/P_osm); positive = dilute urine excreting free water (diabetes insipidus, polydipsia, water-load recovery), negative = concentrated urine conserving free water (dehydration, SIADH). Electrolyte-free: eC_H₂O = V·(1 − (U_Na + U_K)/P_Na), which better predicts the direction of serum sodium change — a negative eC_H₂O means the urine is electrolyte-free-water-rich and tends to raise serum Na⁺, informing IV fluid choice. Optional Na/K inputs enable the electrolyte-free calculation. Derived from Rose, Shimizu 2002 (Nephron), and NephSIM. Point estimate; interpret with full clinical context. Not medical advice. - [Mean Arterial Pressure (MAP)](https://elysiatools.com/en/tools/mean-arterial-pressure): Calculate MAP = DBP + (SBP − DBP)/3. Normal 70–100; ≥65 sepsis target; <65 hypoperfusion. Derived from Geddes 1984, SSC 2021, BTF 2017, StatPearls, LITFL. Not medical advice. - [Mean Platelet Volume (MPV) Analyzer](https://elysiatools.com/en/tools/mean-platelet-volume-analyzer): Analyze Mean Platelet Volume (MPV) in fL, an index of platelet production kinetics. Reference range ≈ 7.5–11.5 fL (lab- and method-dependent). Low MPV (< 7.5 fL, small old platelets) indicates suppressed marrow production (aplastic anemia, chemotherapy/radiation, recent platelet transfusion, iron-deficiency regeneration, Wiskott-Aldrich). High MPV (> 11.5 fL, large young platelets) indicates peripheral destruction with compensatory turnover or macrothrombocytopenia (immune thrombocytopenia ITP, post-splenectomy, myeloproliferative neoplasms, severe sepsis in recovery, Bernard-Soulier / MYH9, megaloblastic anemia; elevated MPV after acute MI marks platelet activation and adverse prognosis). Optionally enter the platelet count to refine the differential: low platelets + high MPV → peripheral destruction; low + low → underproduction; high + low → reactive thrombocytosis; high + high → myeloproliferative neoplasm. Pre-analytical caveat: platelets swell in EDTA over ~2 h raising MPV, and values are method-dependent (impedance > optical > immuno) — compare within the same lab and analyzer. Derived from Bath 1996, Leader 2012, Vagdatli 2010, and MDCalc. Not medical advice. - [Plaque Forming Units Calculator (PFU/mL)](https://elysiatools.com/en/tools/plaque-forming-unit): Compute PFU/mL titer from plaque counts, dilution factor, and plated volume, with multi-plate statistics and 30–300 counting-range warnings. - [Pulmonary Vascular Resistance Calculator (PVR)](https://elysiatools.com/en/tools/pulmonary-vascular-resistance): Compute PVR = (mPAP − PCWP) / CO in Wood units and dyn·s/cm⁵. Normal < 3 Wood; elevated in pulmonary hypertension. Derived from Grossman 1991, Simonneau 2019, Humbert ESC/ERS 2022, StatPearls, LITFL. Not medical advice. - [Pulse Pressure Calculator (PP = SBP − DBP)](https://elysiatools.com/en/tools/pulse-pressure-calculator): Calculate PP = SBP − DBP and MAP = DBP + PP/3. Normal ~30–40 mmHg; wide PP → high SV or stiff arteries; narrow PP → low SV. Pulsus paradoxus flags tamponade/asthma/PE. Derived from McDonald's, Franklin 1999, Blacher 1999, StatPearls, LITFL. Not medical advice. ## Samples - [Web Image Processing Python Samples](https://elysiatools.com/en/samples/web-image-processing-python): Web Python image processing examples using PIL/Pillow including reading, saving, resizing, and format conversion - [Android Image Processing Java Samples](https://elysiatools.com/en/samples/android-image-processing-java): Android Java image processing examples including reading/saving images, scaling, and format conversion - [Android Image Processing Kotlin Samples](https://elysiatools.com/en/samples/android-image-processing-kotlin): Android Kotlin image processing examples including reading/saving images, scaling, and format conversion - [Web Image Processing Rust Samples](https://elysiatools.com/en/samples/web-image-processing-rust): Web Rust image processing examples including image read/save, scaling, and format conversion ## Related content - [Critical Care Blood Gas, Oxygenation, and Hemodynamics Calculators](https://elysiatools.com/en/hubs/critical-care-blood-gas-oxygenation-hemodynamics): Connect arterial blood gas, acid-base, oxygenation, cardiac output, and vascular resistance calculations in one focused critical-care workflow. - [Barcode, QR Code, and Label Tools](https://elysiatools.com/en/hubs/barcode-utility): Compare barcode generation, QR code creation and decoding, UPC/EAN validation, WiFi QR sharing, and printable label tools in one hub. - [Audio Encoding and Format Conversion Tools](https://elysiatools.com/en/hubs/audio-convert): Compare audio format conversion, bitrate changes, sample-rate conversion, codec swaps, and export tools in one hub for delivery and archive workflows. - [Image Format Conversion and Animated Export Tools](https://elysiatools.com/en/hubs/image-convert): Compare image format converters for JPG, PNG, GIF, AVIF, WebP, TIFF, ICO, base64, and animation-friendly exports in one hub.