About PeakCalcs

PeakCalcs is a dedicated health and fitness calculator platform built on a single principle: every estimation tool should be transparent about the formula it uses, where that formula comes from, and what its limitations are. The site is built and maintained by one person — a PhD candidate in IT Sciences with a decade of competitive athletic background and an active gym practice. This page explains who that is, why it matters for a health-related calculator site, and how PeakCalcs is built.

Who Builds PeakCalcs

PeakCalcs is created and maintained by Dan Dadovic, based in Northumberland, United Kingdom. Dan is a Commercial Director at Ezoic — a digital publishing and ad monetisation platform — and a PhD candidate in IT Sciences. The PhD is in progress, not yet awarded; the research focus sits at the intersection of data modelling, statistical validation, and large-scale web application architecture. These are the core technical skills that make a calculator accurate: implementing a published formula correctly, handling unit conversions without rounding drift, and validating outputs against known reference values.

The track record for this approach is the wider portfolio. Dan built CalculatorCorp.com — a portfolio of more than 4,300 calculator pages serving hundreds of thousands of monthly visitors across cooking, electrical, construction, and printing niches. PeakCalcs is the dedicated health and fitness vertical within that broader effort. Each site in the portfolio applies the same disciplined approach: peer-reviewed formula sourcing, structured verification testing, and honest scope acknowledgement on every page.

Working at Ezoic provides direct, daily insight into what distinguishes genuinely useful utility tools from thin programmatic content. Engagement metrics, scroll depth, return-visit patterns, and search query alignment are part of the day job. That commercial context shapes how PeakCalcs is built: tools have to actually answer the question a user came with, not merely rank for it.

The Athlete Behind the Numbers

Before the calculators came the sport. Dan spent ten years in competitive whitewater athletics, beginning with kayaking and canoe slalom at Kayak Kanu Club Odra Sisak in Croatia. He later progressed to Rafting Club Matis, where he represented Croatia on the secondary national rafting team in international competition. Competitive paddling at this level is not recreational weekend kayaking. It is a structured sport with periodised strength and conditioning programming, cardiovascular base work, core stability training, and sport-specific skill sessions — managed across an annual cycle that builds toward competition peaks.

The training methodology used by competitive paddlers maps directly onto the calculators built on PeakCalcs. Heart rate zone training was used for aerobic base development. Progressive overload was applied to upper body and core strength work, tracked with one-rep max estimates in exactly the way the PeakCalcs 1RM calculator now models. Macronutrient timing mattered around competition weight categories. Body composition management was a power-to-weight optimisation problem with measurable consequences in race results. The educational content on this site is not assembled from textbook summaries alone — it reflects the lived training experience of someone who has used these methods under competitive pressure.

That training foundation continues today. Dan trains consistently three times per week, structured around compound barbell movements — squat, bench press, deadlift, and overhead press — combined with sport-specific functional work that maintains the conditioning base built during the competitive years. He has also completed formal fitness programming and exercise science courses to bridge the practical athlete experience with evidence-based methodology. The TDEE, macro split, body fat, and progressive overload calculators on this site are built by someone who actually uses them — not by a developer who has never stepped inside a gym.

How PeakCalcs Is Built

Every calculator on PeakCalcs implements a formula drawn exclusively from peer-reviewed scientific publications or official health organisation guidelines. The metabolic rate tools use the Mifflin-St Jeor equation (American Journal of Clinical Nutrition, 1990), the revised Harris-Benedict equation (Roza and Shizgal, 1984), and the Katch-McArdle formula. The one-rep max estimators implement Epley (1985), Brzycki (1993), and Lander. Body fat estimation uses the U.S. Navy circumference method (Hodgdon and Friedl, 1999), Jackson-Pollock skinfold protocols, and the Deurenberg BMI-derived equation. Pregnancy weight gain follows the Institute of Medicine 2009 guidelines. Secondary sources — fitness blogs, social media content, commercial training manuals — are never used as primary references.

Each implementation passes through a structured verification process before going live. Coefficients are checked line by line against the original publication. Known-value tests run reference inputs against expected outputs. Worked examples on every calculator page are run through the actual calculation engine, and any discrepancy is corrected on the narrative side, never on the formula side. The full editorial process — formula selection, implementation, testing, source verification, and health content guardrails — is documented on the Methodology page. Calorie estimates enforce hard minimum floors of 1,200 kcal per day for women and 1,500 kcal per day for men, with warnings that intake below those thresholds requires medical supervision. No clinical or diagnostic tools are built — no GFR calculators, drug dosage tools, medical risk scores, or blood panel interpreters. PeakCalcs estimates; it does not diagnose and it does not prescribe.

Honesty About Limitations

A final note on scope, because it matters more than any other paragraph on this page. Dan is not a medical doctor, registered dietitian, or certified personal trainer. He is a competitive athlete turned technologist who builds precision tools based on the same peer-reviewed science that qualified professionals use. Every calculator on this site includes a category caveat appropriate to its content area, links to original published sources, and explicit direction to consult a qualified professional — an obstetrician, a registered dietitian, a certified strength coach, a physician — before acting on any result in a way that affects health. The tools here are estimation aids for informed adults. They are not a substitute for professional assessment, and they are never positioned as one.

Every calculator and article on PeakCalcs is independently reviewed by an academic in the relevant subject area. Two reviewers cover the full PeakCalcs scope between them: Dr. Damir Vučić(PhD, Physical & Health Education, FOI Zagreb) for body composition, training, and exercise science content; and Prof. Zvonimir Šatalić, PhD(Laboratory for Nutrition Science, Faculty of Food Technology and Biotechnology, University of Zagreb) for sports nutrition, macros, and dietary assessment content. Each calculator and blog post is assigned to one reviewer based on topic fit, and that reviewer's credit is surfaced on the page itself.

The review process is part of a broader commitment to evidence-based content. Dan builds the calculators based on peer-reviewed formulas; the assigned reviewer verifies that the implementations are scientifically sound, that cited publications match the formulas actually used, and that the educational content accurately represents the underlying science. Worked examples, health caveats, and formula selection rationale all fall within the scope of the review.

Neither reviewer is employed by PeakCalcs. Their review is an independent academic verification — similar to an external examiner role — which is why each reviewer's credentials and affiliation are surfaced on every page they have reviewed alongside the author bio. Full reviewer bios, their respective scopes, and source links are on the Reviewers page.

It is important to be explicit about what this review does and does not mean. The reviewers confirm exercise science accuracy and nutritional soundness within their respective scopes; their review does not constitute medical endorsement, personalised health advice, or a guarantee of suitability for any individual user. PeakCalcs calculators remain population-level estimation tools. Users should consult qualified healthcare professionals — physicians, registered dietitians, obstetricians, certified trainers — for advice specific to their own medical or nutritional circumstances.

Get in Touch

Questions, feedback, or corrections are welcome. If a formula has been updated, a citation needs revising, or a calculation produces unexpected results, please get in touch. Accuracy matters more than any other feature on this site.

Contact: contact@peakcalcs.com