Calculators, generators and checkers for every stage of a study: before you collect data, while validating your instrument, when you analyze and interpret, and when you publish. All free and in your browser.
Every tool, by research stage
Before you collect data
The Methodologist (AI): Paste your project or protocol BEFORE you collect data and get the design flaws, a sample-size check, an analysis-plan review and a preregistration draft.
Ethics committee simulator (AI): Describe your project and anticipate the committee’s objections, the paragraphs missing from your application, and whether you work with a vulnerable population.
Sample size calculator: How many participants you need given test, effect size and power.
McDonald's omega (ω + AVE): For when a reviewer objects that Cronbach's alpha does not hold: McDonald's omega (composite reliability) and AVE from your CFA loadings.
Z-score, percentile & T-score converter: To place one person's score within their group's norms: convert between Z, percentile, T, IQ and stanine instantly.
Cohen's kappa calculator: Agreement between two raters from a 2×2 table, with 95% CI and Landis-Koch interpretation.
Content validity calculator (Aiken / CVI): Turn your expert panel's ratings into the content-validity evidence your paper needs: Aiken's V with 95% CI, I-CVI and S-CVI.
EFA report in APA 7: Paste your exploratory factor analysis output and generate the results section written in APA 7.
CFA report in APA 7: Paste your CFA fit indices and loadings and generate the results section written in APA 7.
Measurement invariance checker: Before you compare means between groups, show the scale measures the same in both: configural, metric, scalar and strict, with ΔCFI and ΔRMSEA.
Item analysis calculator: Which questions of your exam, or items of your scale, drag reliability down: difficulty, discrimination and alpha-if-deleted, with the appendix table.
ICC calculator: Inter-rater or test-retest reliability when what you measure is continuous: all six McGraw & Wong ICC forms with 95% CIs, and which one is yours.
Krippendorff's alpha calculator: For when Cohen's kappa falls short: agreement between coders with more than two raters, uncoded cells and scales that are not nominal.
Norms table generator: Turn raw scores into percentiles and standard scores, with the norms table ready to use.
Bland-Altman calculator: Can you swap one instrument for the other without changing your conclusions? Bias with 95% CI, limits of agreement and proportional bias.
Analyze and interpret
Interpret your output (AI): Paste your SPSS, JASP, jamovi or R output and get it explained in plain language, plus the APA 7 sentence ready to paste.
Explain this paragraph (AI): Paste a results paragraph from someone else’s paper that you cannot follow and get it explained in plain language, with a glossary of the technical terms.
Effect size calculator: The effect size APA 7 and any reviewer will ask for next to your p: Cohen's d, partial eta² or the odds ratio from your results.
APA 7 formatter: Enter statistics and get APA 7 text ready to paste.
Confidence interval calculator: The interval of a mean, a proportion, a mean difference or a correlation, with the APA 7 sentence.
t, z, chi-square and F tables: The four distribution tables with how to read them, plus the critical value or exact p value of your statistic.
Normality interpreter: Shapiro-Wilk or Kolmogorov-Smirnov with clear interpretation.
SEM model comparator: When you have two or three versions of the same model and must decide which one you keep: a traffic light per index (Hu & Bentler) and ΔAIC.
Effect size conversions: From t to d, F to partial η², chi-square to V, OR to RR and nine more, each with its formula, its assumption and how to report it.
Universal APA table (t, ANOVA, χ²): One tool for the three tables people ask for most: t-test, ANOVA and chi-square, in APA 7 and ready for Word.
APA descriptive statistics table: Paste your Excel or SPSS columns and get Table 1: n, M, SD, median, range, skewness and kurtosis in APA 7, with a non-normality warning.
APA logistic regression table: B, SE, Wald, p, odds ratio and 95% CI from SPSS or R output, with the model χ² and an events-per-variable check.
APA nonparametric tests table: Mann-Whitney, Wilcoxon or Kruskal-Wallis with medians, IQRs and the effect size (r or ε²) SPSS does not give you.
Meta-analysis and systematic review
Heterogeneity calculator: Are your studies alike enough to pool? I², H² and Cochran's Q; with the study table, τ² and the prediction interval too.
PRISMA flow diagram generator: Identification, screening, eligibility and included, with every count computed automatically. Download as a PNG, no watermark.
Effect size from text: When the paper only reports t(48) = 2.31, with no means or SDs: paste the sentence and get Cohen's d, Hedges' g, r and partial eta² with 95% CIs.
Clinical research
Sensitivity & specificity calculator: How well your test performs against the reference standard: sensitivity, specificity, PPV and NPV with 95% CIs, plus likelihood ratios and Youden.
Odds ratio & risk ratio calculator: How much likelier the outcome is in the exposed: OR and RR with 95% CIs from a 2×2 table, plus risk difference and NNT.
ROC curve calculator: When your test gives a continuous score and you do not know where to cut: AUC with 95% CI, the optimal Youden cutoff and a downloadable PNG curve.
Kaplan-Meier calculator: Time until something happens, with follow-up that runs out first: survival curve with 95% CI, median, log-rank and hazard ratio.
Pre-post effect size with control: Morris’s dppc2 with 95% CI for pretest-posttest-control designs: the right one for educational interventions.
Normalized gain (Hake): How much your students learned of what they could learn: g per student and per class, the two-group comparison and the pre-post diagram as a PNG.
Cohen’s d to months of progress: Translate effect sizes into what a school understands: months of progress (EEF), U3, probability of superiority and percentiles.
How many classrooms do I need?: Classrooms per arm for your intervention given expected effect, class size and ICC, with typical education values.
Test blueprint generator: Distribute your exam items across content areas and cognitive levels by weight, totals guaranteed, Word-ready table.
Teaching dataset generator: Reproducible simulated data for your statistics classes: pick the design and the effect, and get data that shows exactly what you want to teach.
Publish, defend and monitor
Previum: Upload your manuscript and get the critiques a Q1 Reviewer 2 will likely raise, before you submit.
Thesis defense simulator: Upload your thesis and generate the questions your committee is likely to ask, and how to frame them.
Final project defense, BA/MA: The same for an undergraduate or master's project, pitched at what a panel actually expects at that level.
Review one section (AI): Paste the Method, the Results or whichever section you are writing and get the first objection a reviewer would raise, with the exact sentence from your text.
Which journal should I submit to?: Paste your abstract and up to three journals: we cross-check each against OpenAlex and DOAJ in real time to see whether they publish work like yours and what flags to check first.
Reference checker: Check whether the references in your bibliography actually exist: Crossref, OpenAlex, PubMed, Semantic Scholar, DOAJ, OpenLibrary, Google Books and arXiv, with the real DOI when there is one and a flag when the paper is retracted.
Check my statistics: Paste your Results section: every p is recomputed from its t, F, chi-square, r or z (statcheck), the GRIM test checks whether your means are possible with your n, and the N is cross-checked between sections. In your browser, no sign-up.
CONSORT, STROBE, PRISMA and STARD checklist checker: Paste the manuscript and see which items of the guideline appear in the text and which do not, with the sentence that supports each one. Only the items a text search can decide, and it says which ones it cannot.
Response to reviewers table (Word): Paste the decision letter and get the point-by-point table, one comment per row with its number (R1.1, R2.3…), ready to answer in Word. It never leaves your browser.
Cover letter template: The cover letter for the journal by article type (original, systematic review, case report, transfer or revised version), ready to copy or download in Word.
The Literature Watch: A weekly email with what has been published on your topic, already summarized: what they found and whether it forces you to change anything you have written.