EC50 Calculator

EC₅₀ represents the concentration at which a substance exerts half of its maximal response. This value is particularly important in pharmacology, because it serves as an indication of drug potency. Traditionally, EC₅₀ is expressed as a molar concentration.

This calculator generates an EC₅₀ value typically thought of as the relative EC₅₀. For technical assistance on using this calculator, please contact websupport@aatbio.com.

Data Entry

Feedback

Have a question or a feature request about this tool? Feel free to reach out to us and let us know! We're always looking for ways to improve!

Email address

References

This online resource may be cited as follows

MLA	"Quest Graph™ EC50 Calculator." AAT Bioquest, Inc., 29 Oct. 2025, https://www.aatbio.com/tools/ec50-calculator.
APA	AAT Bioquest, Inc. (2025, October 29). Quest Graph™ EC50 Calculator. AAT Bioquest. https://www.aatbio.com/tools/ec50-calculator.
BibTeX	EndNote	RefMan

This online resource has been cited in 100 publications, including

Riboflavin-based photodynamic inactivation against Rhizopus (R. stolonifer) fungus for vegetables preservation

Authors:

Rodoni, Luis Mar{\'\i}a and Pintos, Federico Mart{\'\i}n and Larran, Silvina and Lorente, Carolina and Hevia, Alejandra In{\'e}s and Lemoine, Mar{\'\i}a Laura

Journal:

Postharvest Biology and Technology (2026): 113945

In vitro cytotoxicity (irritant potency) of toothpaste ingredients

Authors:

Kasi, Shaira R and Roffel, Sanne and {\"O}zcan, Mutlu and Gibbs, Susan and Feilzer, Albert J

Journal:

PloS one (2025): e0318565

Anticancer effect of a single-chain variable fragment against pro-matrix metalloproteinase-7 in colon cancer

Authors:

Min, Shinhye and Jang, Bohee and Yun, Ji-Hye and Yang, Hyeonju and Sung, Jee Young and Lim, Ga-Eun and Kim, Yong-Nyun and Lee, Weontae and Oh, Eok-Soo

Journal:

Matrix Biology (2025): 125--134

Ispitivanje citotoksi{\v{c}}nog potencijala gljiva za medicinsku upotrebu in vitro u ljudskih stani{\v{c}}nih linija raka dojke

Authors:

Topalovi{\'c}, Dijana and {\v{Z}}ivkovi{\'c}, Lada and Borozan, Sun{\v{c}}ica and Santibanez, Juan F and Spremo-Potparevi{\'c}, Biljana

Journal:

Arhiv za higijenu rada i toksikologiju (2024): 297--301

Evaluation of Pinocembrin Dihydrochalcone Properties for Potential Use as a Biopesticide

Authors:

{\k{a}} gwa-Becker, Magdalena Dzi and Oleszek, Marta and Ukalska-Jaruga, Aleksandra and Kucharski, Mariusz

Characteristics of Zymoseptoria tritici isolates from the Russian Federation and the Republic of Kazakhstan by azoxystrobin sensitivity

Authors:

Zeleneva, Yuliya and Zubko, Natalya and Kokhmetova, Alma and Konkova, Elmira and Kumarbayeva, Madina

Human microbiome derived synthetic antimicrobial peptides with activity against Gram-negative, Gram-positive, and antibiotic resistant bacteria

Authors:

Mousa, Walaa K and Shaikh, Ashif Y and Ghemrawi, Rose and Aldulaimi, Mohammed and Al Ali, Aya and Sammani, Nour and Khair, Mostafa and Helal, Mohamed I and Al-Marzooq, Farah and Oueis, Emilia

Journal:

RSC Medicinal Chemistry (2024)

Deciphering Angiotensin Converting Enzyme 2 (ACE2) Inhibition Dynamics: Carnosine's Modulatory Role in Breast Cancer Proliferation--A Clinical Sciences Perspective

Authors:

Melhem, Sarah A and Saadah, Loai M and Attallah, Zeena S and Mansi, Iman A and Hamed, Saja H and Talib, Wamidh H

Journal:

Heliyon (2024)

Identification of Environmental Compounds That May Trigger Early Female Puberty by Activating Human GnRHR and KISS1R

Authors:

Yang, Shu and Zhang, Li and Khan, Kamal and Travers, Jameson and Huang, Ruili and Jovanovic, Vukasin M and Veeramachaneni, Rithvik and Sakamuru, Srilatha and Tristan, Carlos A and Davis, Erica E and others,

Journal:

Endocrinology (2024): bqae103

Development of novel imipridone derivatives with potent anti-cancer activities as human caseinolytic peptidase P (hClpP) activators

Authors:

Zhang, Yanzhi and Jiang, Jinxin and Ding, Hao and Li, Qiannan and Xiao, Yibei and Sun, Haiying

Journal:

Bioorganic Chemistry (2024): 107765

Utilizing Foam-Structured Hydroxypropyl Methylcellulose Oleogels with Curcumin for Deep-Fried Chicken Nuggets in Carnauba Wax-Canola Oil Oleogel

Authors:

Mahmud, Niaz and Islam, Joinul and Tahergorabi, Reza

Journal:

Journal of Agriculture and Food Research (2024): 101364

Metabolic reprogramming of poly (morpho) nuclear giant cells determines glioblastoma recovery from doxorubicin-induced stress

Authors:

Pude{\l}ek, Maciej and Ryszawy, Damian and Piwowarczyk, Katarzyna and Lasota, S{\l}awomir and Madeja, Zbigniew and K{\k{e}}dracka-Krok, Sylwia and Czy{\.z}, Jaros{\l}aw

Journal:

Journal of Translational Medicine (2024): 757

Functional distinction in oncogenic Ras variant activity in Caenorhabditis elegans

Authors:

Lyu, Haimeng and Chamberlin, Helen M

Journal:

Disease Models \& Mechanisms (2024)

Molecules targeting a novel homotrimer cavity of Spike protein attenuate replication of SARS-CoV-2

Authors:

Daniels, Alison and Padariya, Monikaben and Fletcher, Sarah and Ball, Kathryn and Singh, Ashita and Carragher, Neil and Hupp, Ted and Tait-Burkard, Christine and Kalathiya, Umesh

Journal:

Antiviral Research (2024): 105949

Efficacy and Safety of Asparagusic Acid against Echinococcus multilocularis In Vitro and in a Murine Infection Model

Authors:

Lu, Zhuanhong and Wang, Yating and Liu, Chuanchuan and Fan, Haining

Journal:

Tropical Medicine and Infectious Disease (2024): 110

Large-scale deorphanization of Nematostella vectensis neuropeptide G protein-coupled receptors supports the independent expansion of bilaterian and cnidarian peptidergic systems

Authors:

Thiel, Daniel and Guerra, Luis Alfonso Ya{\~n}ez and Kieswetter, Amanda and Cole, Alison G and Temmerman, Liesbet and Technau, Ulrich and J{\'e}kely, G{\'a}sp{\'a}r

Journal:

eLife (2024): RP90674

Synthesis, docking study, and antitumor evaluation of benzamides and oxadiazole derivatives of 3-phenoxybenzoic acid as VEGFR-2 inhibitors

Authors:

Heriz, Mohammad H and Mahmood, Ammar AR and Yasin, Salem R and Saleh, Khaled M and AlSakhen, Mai F and Kanaan, Sana I and Himsawi, Nisreen and Saleh, Abdulrahman M and Tahtamouni, Lubna H

Journal:

Drug Development Research (2024): e22186

Synthesis, Structural Characterization, and Quantum Chemical Study of the 7-Acetyl-5-nitrobenzofurans as Anticancer Agents with Antioxidant Properties

Authors:

Maluleka, Marole M and Segodi, Redolf S and Mphahlele, Malose J and Mbazima, Vusi G and Elhenawy, Ahmed A and Monchusi, Bernice A

Journal:

Journal of Molecular Structure (2024): 138398

Bioactive Properties of Venoms Isolated from Whiptail Stingrays and the Search for Molecular Mechanisms and Targets

Authors:

Doupnik, Craig A and Luer, Carl A and Walsh, Catherine J and Restivo, Jessica and Brick, Jacqueline Xinlan

Genome-wide methylation profiling of Peripheral T-cell lymphomas identifies TRIP13 as a critical driver of tumor proliferation and survival

Authors:

Nowialis, Pawel and Tobon, Julian and Lopusna, Katarina and Opavska, Jana and Badar, Arshee and Chen, Duo and Abdelghany, Reem and Pozas, Gene and Fingeret, Jacob and Noel, Emma and others,

The allelopathic potential of red macroalga Pyropia haitanensis solvent extracts on controlling bloom-forming microalgae: Insights into the inhibitory compounds

Authors:

Patil, Vishal and Huang, Lu and Liang, Junrong and Sun, Lin and Wang, Dazhi and Gao, Yahui and Chen, Changping

Journal:

Ecotoxicology and Environmental Safety (2024): 116083

SARS-CoV-2 Specific Nanobodies Neutralize Different Variants of Concern and Reduce Virus Load in the Brain of h-ACE2 Transgenic Mice

Authors:

Pavan, Mar{\'\i}a Florencia and Bok, Marina and Betanzos San Juan, Rafael and Malito, Juan Pablo and Marcoppido, Gisela Ariana and Franco, Diego Rafael and Militelo, Daniela Ayelen and Schammas, Juan Manuel and Bari, Sara Elizabeth and Stone, William and others,

Journal:

Viruses (2024): 185

The anti-proliferative effects of a frankincense extract in a window of opportunity phase ia clinical trial for patients with breast cancer

Authors:

Valente, Ingrid V Bonilla and Garcia, Denise and Abbott, Andrea and Spruill, Laura and Siegel, Julie and Forcucci, Jessica and Hanna, George and Mukherjee, Rupak and Hamann, Mark and Hilliard, Eleanor and others,

Journal:

Breast Cancer Research and Treatment (2024): 1--10

Chemotaxonomy, antibacterial and antioxidant activities of selected aromatic plants from Tabuk region-KSA

Authors:

Elbalola, Abdelrahim A and Abbas, Zahid Khorshid

Journal:

Heliyon (2023)

The Monothiol Glutaredoxin Grx4 Influences Iron Homeostasis and Virulence in Ustilago maydis

Authors:

McCotter, Sean W and Kretschmer, Matthias and Lee, Christopher WJ and Heimel, Kai and Kronstad, James W

Journal:

Journal of Fungi (2023): 1112

Immunotherapy of cytomegalovirus infection by low-dose adoptive transfer of antiviral CD8 T cells relies on substantial post-transfer expansion of central memory cells but not effector-memory cells

Authors:

Holtappels, Rafaela and Becker, Sara and Hamdan, Sara and Freitag, Kirsten and Podlech, J{\"u}rgen and Lemmermann, Niels A and Reddehase, Matthias J

Journal:

PLoS pathogens (2023): e1011643

Paste experimental data into the box on the right. Data can be copied directly from Excel columns. Data can also be comma-separated, tab-separated or space-separated values. If entering data manually, only enter one X-Value per line. Replicates can be graphed simultaneously. Graph will generate error bars based on the standard error of the mean (SEM). Simply paste or enter all data columns to begin. Format should be as follows:
Concentration Response 1 Response 2 …
C₁ R1₁ R2₁ …
C₂ R1₂ R2₂ …
C₃ R1₃ R2₃ …
… … … …
Users can graph up to three data sets on the same graph for comparison purposes. To add a new data set, press the "+" tab above the data entry area. Data sets can be renamed by double clicking the tab. Each dataset will generate a corresponding EC₅₀ value as well as the equation for the best fit line.
Verify your data is accurate in the table that appears.
Press the "Calculate EC₅₀" button to display results, including calculations and graph.

Four Parameter Logistic (4PL) Regression
Calculate a best fit line with minimum, maximum, Hill coefficient and inflection point
IC50 Calculator
Calculate the IC50 of a dataset
Linear Regression
Calculate the linear regression of a dataset
Log-Log Regression
Best fit line with log-log axis; also known as a power regression
Logistic Regression (Logit)
Non-linear regression to model binary outcomes
Polynomial Regression
Determine the best fit line using linear, quadratic, cubic and quartic equations

Concentration	Response 1	Response 2	…
C₁	R1₁	R2₁	…
C₂	R1₂	R2₂	…
C₃	R1₃	R2₃	…
…	…	…	…

How to use this tool

Related tools