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 websupport@aatbio.com.

How to use this tool

1. 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:

ConcentrationResponse 1Response 2...

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.

2. Verify your data is accurate in the table that appears.

3. Press the "Calculate LD50" button to display results, including calculations and graph.

Data Entry

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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!

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This online tool may be cited as follows


"Quest Graph™ LD50 Calculator." AAT Bioquest, Inc.9 Dec2023https://www.aatbio.com/tools/ld50-calculator.


AAT Bioquest, Inc. (2023December 9). Quest Graph™ LD50 Calculator. AAT Bioquest. https://www.aatbio.com/tools/ld50-calculator.

This online tool has been cited in 17 publications, including

The best of both worlds? Rattlesnake hybrid zones generate complex combinations of divergent venom phenotypes that retain high toxicity
Authors: 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 P
Journal: Biochimie (2023)
Snakes on a plain: biotic and abiotic factors determine venom compositional variation in a wide-ranging generalist rattlesnake
Authors: 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): 136
Induction of SARS-CoV-2 N-specific CD8+ T cell immunity in lungs by engineered extracellular vesicles associates with strongly impaired viral replication
Authors: 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--01
Antiviral effect of SARS-CoV-2 N-specific CD8+ T cells induced in lungs by engineered extracellular vesicles
Authors: 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): 83
Antitumor Effect of Novel Berberine Analogues in a Canine Mammary Tumor Cell Line and in Zebrafish Reporters via Wnt/$\beta$-Catenin and Hippo Pathways
Authors: 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: (2023)
Acute and Reproductive Toxicity of Freeze-dried and Steam-dried Extracts of Tradomal{\textregistered} in Drosophila melanogaster
Authors: Salaudeen, Maryam Adenike and Sadiq, Salamatu Onini and Magaji, Mohammad Garba
Journal: Pharmacology and Toxicology of Natural Medicines (ISSN: 2756-6838) (2023): 11--15
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)
MDN-6, a Possible Therapeutic Candidate for Multidrug-Resistant and Extensively Drug-Resistant Mycobacterium tuberculosis
Authors: Islam, Imtiazul and Seo, Hoonhee and Kim, Sukyung and Lee, YoungKyoung and Sadu, Venkata S and Lee, Kee-In and Song, Ho-Yeon
Journal: Jundishapur Journal of Microbiology (2022)
Impact of oxytetracycline exposure on the digestive system microbiota of Daphnia magna
Authors: Lovern, Sarah B and Van Hart, Rochelle
Journal: Plos one (2022): e0265944
CuO 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, Maria
Journal: Environmental Nanotechnology, Monitoring \& Management (2022): 100751
Short-term metabolic resistance inductive effect of different agrochemical groups on Anopheles gambiae mosquitoes
Authors: 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 S
Journal: Wellcome Open Research (2021): 147
Evaluation 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 H
Journal: Environmental Science and Pollution Research (2021): 1--9
Chronic stimulation of group II metabotropic glutamate receptors in the medulla oblongata attenuates hypertension development in spontaneously hypertensive rats
Authors: Hsu, Julia Chu-Ning and Sekizawa, Shin-ichi and Tochinai, Ryota and Kuwahara, Masayoshi
Journal: PloS one (2021): e0251495
Synergy between Florfenicol and Aminoglycosides against Multidrug-Resistant Escherichia coli Isolates from Livestock
Authors: Kim, Shukho and Woo, Jung Hwa and Jun, So Hyun and Moon, Dong Chan and Lim, Suk-Kyung and Lee, Je Chul
Journal: Antibiotics (2020): 185
Gamma radiation tolerance and protein carbonylation caused by irradiation of resting cysts in the free-living ciliated protist Colpoda cucullus
Authors: Saito, Ryota and Koizumi, Ryota and Sakai, Tatsuya and Shimizu, Taiga and Ono, Taiki and Sogame, Yoichiro
Journal: Acta Protozoologica (2020): 67--75
Discovery of in vivo virulence genes of obligatory intracellular bacteria by random mutagenesis
Authors: Bekebrede, Hannah and Lin, Mingqun and Teymournejad, Omid and Rikihisa, Yasuko
Journal: Frontiers in Cellular and Infection Microbiology (2020): 2
Environmental Nanotechnology, Monitoring \& Management
Authors: Abdeen, Z and Mohammad, SG and Mahmoud, MS
Journal: (2014)