LD50 Calculator - AAT Bioquest

LD50 Calculator

LD50 stands for "lethal dose 50%" or "median lethal dose". It is given with respect to ingestion of a substance after a specified amount of time and is the dose at which that substance kills half the members of a tested population. This value is very important in toxicology as it gives an indication of substance toxicity. The LD50 is inversely proportional to toxicity. A substance with a lower LD50 is more toxic than one which has a higher LD50. For a database of LD50 values for common compounds, please click here.

Traditionally, the doses (x-value) are entered as a ratio of the mass of the substance divided by the mass of the test subject. This corrects for differences in test subject body mass. The responses (y-value) are typically entered as percentage of population killed (range from 0 to 100). This will yield an upward-slopping sigmoidal curve. If percentage survival is used instead, a downward-slopping sigmoidal curve will be generated.

For technical assistance on using this calculator, please contact [email protected].

Data EntryLoad DataSave DataImport from file​​Process dataFeedbackHave 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 addressEmail addressSubmit requestReferencesThis online resource may be cited as follows

MLA	"Quest Graph™ LD50 Calculator." AAT Bioquest, Inc., 7 Mar. 2026, https://www.aatbio.com/tools/ld50-calculator.
APA	AAT Bioquest, Inc. (2026, March 7). Quest Graph™ LD50 Calculator. AAT Bioquest. https://www.aatbio.com/tools/ld50-calculator.
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This online resource has been cited in 32 publications, includingUVB-Induced Genotoxic Stress Activates the DNA Damage Response and Innate Immune Pathways in Sea Urchin CoelomocytesAuthors: Kell, Riss M and Weber, Margaret K and Escalante, Rosa Y and Silva, Jeffrey C and Bodnar, Andrea GJournal: bioRxiv (2026): 2026--01De novo designed proteins neutralize lethal snake venom toxinsAuthors: V{\'a}zquez Torres, Susana and Benard Valle, Melisa and Mackessy, Stephen P and Menzies, Stefanie K and Casewell, Nicholas R and Ahmadi, Shirin and Burlet, Nick J and Muratspahi{\'c}, Edin and Sappington, Isaac and Overath, Max D and others, Journal: Nature (2025): 1--7Assessing the Impact of Collection, Production, and Storage of Platelet Concentrates on Bacterial Contamination and Product SafetyAuthors: Kumaran, DiliniThe Local Anesthetic Activity of 4-(Naphthalen-1-yloxy) but-2-yn-1-yl)-containing Piperidine Derivatives in Experimental Animal ModelsAuthors: Khaiitova, Malika and Sycheva, Yelena and Trubachev, Vas{\i}l{\i}y and Satbayeva, Elm{\i}ra and Yu, Valent{\i}na and Nurgozh{\i}n, Talgat and Stankev{\i}{\v{c}}{\i}us, Edgaras and Gassanov, Yeskendir and Utelbayeva, Zauresh and Tass{\i}bekov, Kha{\i}darJournal: Fabad Journal of Pharmaceutical Sciences (2024): 465--480Disruption of tRNA biogenesis enhances proteostatic resilience, improves later-life health, and promotes longevityAuthors: Malik, Yasir and Kulaberoglu, Yavuz and Anver, Shajahan and Javidnia, Sara and Borland, Gillian and Rivera, Rene and Cranwell, Stephen and Medelbekova, Danel and Svermova, Tatiana and Thomson, Jackie and others, Journal: PLoS biology (2024): e3002853De novo designed proteins neutralize lethal snake venom toxinsAuthors: Baker, David and Torres, Susana Vazquez and Valle, Melisa Benard and Mackessy, Stephen and Menzies, Stefanie and Casewell, Nicholas and Ahmadi, Shirin and Burlet, Nick and Muratspahi{\'c}, Edin and Sappington, Isaac and others, Potential Bioprospecting Within Vemons of Rear-Fanged SnakesAuthors: Harvey, Tanner MilbankNaja nigricincta nigricincta venom, a murine model. Evaluation of skeletal and cardio-myonecrosis, kidney injury and inflammatory response along with neutralisation efficacy by the SAIMR/SAVP-and EchiTAb-Plus-ICP polyvalent antivenoms.Authors: Saaiman, Esta L and Naidoo, Vinny and Botha, Christo JJournal: Toxicon (2024): 107719Bumblebees are resilient to neonicotinoid-fungicide combinationsAuthors: Schuhmann, Antonia and Schulte, Janna and Feldhaar, Heike and Scheiner, RicardaJournal: Environment International (2024): 108608In vivo functional immunoprotection correlates for vaccines against invasive bacteriaAuthors: Tian, Xianbin and Wang, Juanjuan and Chen, Haoze and Ding, Ming and Jin, Qian and Zhang, Jing-RenJournal: Vaccine (2024)In vivo rescue of arboviruses directly from subgenomic DNA fragmentsAuthors: Cochin, Maxime and Driouich, Jean-S{\'e}lim and Moureau, Gr{\'e}gory and Piorkowski, G{\'e}raldine and de Lamballerie, Xavier Nicolas and Nougairede, AntoineJournal: bioRxiv (2024): 2024--01Modified Vaccine Vectors to Understand Adjuvant Functions of Listeria During Chronic SchistosomiasisAuthors: Norwood, Stephanie KAntitumor Effect of Berberine Analogs in a Canine Mammary Tumor Cell Line and in Zebrafish Reporters via Wnt/$\beta$-Catenin and Hippo PathwaysAuthors: Sammarco, Alessandro and Beffagna, Giorgia and Sacchetto, Roberta and Vettori, Andrea and Bonsembiante, Federico and Scarin, Giulia and Gelain, Maria Elena and Cavicchioli, Laura and Ferro, Silvia and Geroni, Cristina and others, Journal: Biomedicines (2023): 3317Antitumor Effect of Novel Berberine Analogues in a Canine Mammary Tumor Cell Line and in Zebrafish Reporters via Wnt/$\beta$-Catenin and Hippo PathwaysAuthors: Sammarco, Alessandro and Beffagna, Giorgia and Sacchetto, Roberta and Vettori, Andrea and Bonsembiante, Federico and Scarin, Giulia and Gelain, Maria Elena and Cavicchioli, Laura and Ferro, Silvia and Geroni, Cristina and others, Acute and Reproductive Toxicity of Freeze-dried and Steam-dried Extracts of Tradomal{\textregistered} in Drosophila melanogasterAuthors: Salaudeen, Maryam Adenike and Sadiq, Salamatu Onini and Magaji, Mohammad GarbaJournal: Pharmacology and Toxicology of Natural Medicines (ISSN: 2756-6838) (2023): 11--15The best of both worlds? Rattlesnake hybrid zones generate complex combinations of divergent venom phenotypes that retain high toxicityAuthors: Smith, Cara F and Nikolakis, Zachary L and Perry, Blair W and Schield, Drew R and Meik, Jesse M and Saviola, Anthony J and Castoe, Todd A and Parker, Joshua and Mackessy, Stephen PJournal: Biochimie (2023)Snakes on a plain: biotic and abiotic factors determine venom compositional variation in a wide-ranging generalist rattlesnakeAuthors: Smith, Cara F and Nikolakis, Zachary L and Ivey, Kathleen and Perry, Blair W and Schield, Drew R and Balchan, Neil R and Parker, Joshua and Hansen, Kirk C and Saviola, Anthony J and Castoe, Todd A and others, Journal: BMC biology (2023): 136Antiviral effect of SARS-CoV-2 N-specific CD8+ T cells induced in lungs by engineered extracellular vesiclesAuthors: Manfredi, Francesco and Chiozzini, Chiara and Ferrantelli, Flavia and Leone, Patrizia and Pugliese, Katherina and Spada, Massimo and Di Virgilio, Antonio and Giovannelli, Andrea and Valeri, Mauro and Cara, Andrea and others, Journal: npj Vaccines (2023): 83Induction of SARS-CoV-2 N-specific CD8+ T cell immunity in lungs by engineered extracellular vesicles associates with strongly impaired viral replicationAuthors: Manfredi, Francesco and Chiozzini, Chiara and Ferrantelli, Flavia and Leone, Patrizia and Pugliese, katherina and Spada, Massimo and Di Virgilio, Antonio and Giovannelli, Andrea and Valeri, Mauro and Cara, Andrea and others, Journal: bioRxiv (2023): 2023--01CuO NPs-induced damage to testes and deregulation of the antioxidant system in wild terrestrial organism Blaps sulcata (Coleoptera: Tenebrionidae)Authors: El-Samad, Lamia M and El-Gendy, Amel H and Abdel-Moneim, Ashraf Mohamed and El-Ashram, Saeed and Augustyniak, MariaJournal: Environmental Nanotechnology, Monitoring \& Management (2022): 100751Impact of oxytetracycline exposure on the digestive system microbiota of Daphnia magnaAuthors: Lovern, Sarah B and Van Hart, RochelleJournal: Plos one (2022): e0265944MDN-6, a Possible Therapeutic Candidate for Multidrug-Resistant and Extensively Drug-Resistant Mycobacterium tuberculosisAuthors: Islam, Imtiazul and Seo, Hoonhee and Kim, Sukyung and Lee, YoungKyoung and Sadu, Venkata S and Lee, Kee-In and Song, Ho-YeonJournal: Jundishapur Journal of Microbiology (2022)Strong SARS-CoV-2 N-specific CD8+ T immunity induced by engineered extracellular vesicles associates with protection from lethal infection in mice.Authors: Ferrantelli, Flavia and Chiozzini, Chiara and Manfredi, Francesco and Leone, Patrizia and Spada, Massimo and DiVirgilio, Antonio and Giovannelli, Andrea and Sanchez, Massimo and Cara, Andrea and Michelini, Zuleika and others, Journal: bioRxiv (2022)Chronic stimulation of group II metabotropic glutamate receptors in the medulla oblongata attenuates hypertension development in spontaneously hypertensive ratsAuthors: Hsu, Julia Chu-Ning and Sekizawa, Shin-ichi and Tochinai, Ryota and Kuwahara, MasayoshiJournal: PloS one (2021): e0251495Short-term metabolic resistance inductive effect of different agrochemical groups on Anopheles gambiae mosquitoesAuthors: Sadia, Christabelle G and Kouadio, France-Paraudie A and Fodjo, Behi K and Oyou, Sebastien K and Beatrice, Adepo-Gourene A and Koudou, Benjamin G and Mouhamadou, Choua{\"\i}bou SJournal: Wellcome Open Research (2021): 147Evaluation of the acute toxicity of Thymus linearis ethanol extract and its effect on the hemato-biochemical and behavioural response of the Golden mahseer, Tor putitora (Hamilton, 1923)Authors: Shah, Tarang Kumar and Kumar, Avdhesh and Tandel, Ritesh Shantilal and Sarma, Debajit and Bhat, Raja Aadil HJournal: Environmental Science and Pollution Research (2021): 1--9

How to use this tool

• 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 LD50 value as well as the equation for the best fit line.
• Verify your data is accurate in the table that appears.
• Press the "Calculate LD50" button to display results, including calculations and graph.

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