Our Expert Curators

Every calculator on xCalculator is reviewed and endorsed by certified professionals in their field.

Dr. Sarah Chen, RD

Dr. Sarah Chen, RD

Registered Dietitian

Health & Nutrition

Harvard-trained nutrition scientist with 12+ years of clinical experience. Dr. Chen specializes in translating complex nutritional science into actionable tools for everyday health decisions.

RDCNSMS Harvard T.H. Chan School

Calculators:

BMITDEEBody FatWater IntakeMacroProteinFiber
Marcus Webb, CFP®

Marcus Webb, CFP®

Certified Financial Planner

Finance

Wharton graduate with 15+ years helping families achieve financial freedom. Featured in Forbes' '30 Advisors Changing Financial Education'.

CFP®CFA Level IIWharton School

Calculators:

Compound InterestMortgageRetirementLoanDebt Snowball
Prof. Elena Vasquez

Prof. Elena Vasquez

Applied Mathematics Professor

Math & Science

MIT PhD in Applied Mathematics. Teaching calculus and linear algebra for 13+ years. Believes the best tools help you understand the method, not just get the answer.

PhD MITProfessor Westbridge University

Calculators:

PercentageUnit ConverterQuadraticMatrixFactorial
Coach Ryan Okafor

Coach Ryan Okafor

Strength & Conditioning Coach

Fitness

NSCA-CSCS certified with experience training semi-pro athletes and fitness enthusiasts. Uses data-driven methods to optimize performance.

CSCSNASM-CPTBS Exercise Science FSU

Calculators:

Running Pace1RMVO₂ MaxHeart Rate ZonesCalorie Burn
Alex Kim

Alex Kim

UX Researcher & Productivity Expert

Life Tools

Carnegie Mellon HCI graduate. Researches how people use digital tools in daily life. Believes the best tools require zero thinking—the answer appears before you ask.

MS HCI Carnegie MellonProductivity Consultant

Calculators:

AgeTipGPADate DifferenceScreen Time
Dr. Michael Torres

Dr. Michael Torres

Sleep Scientist

Sleep & Recovery

Stanford PhD in Neuroscience specializing in sleep cycles and cognitive performance. Published 30+ peer-reviewed papers on sleep optimization.

PhD Neuroscience StanfordSleep Specialist

Calculators:

Sleep CyclesSleep DebtBACStress Score
Jennifer Lin, CFA

Jennifer Lin, CFA

Investment Advisor

Investment & Planning

Chicago Booth MBA, former BlackRock portfolio manager. Now runs her own advisory firm focused on helping millennials achieve financial independence.

CFACFPMBA Chicago Booth

Calculators:

InflationSavings GoalInvestment ReturnEmergency Fund
Dr. James Wilson

Dr. James Wilson

Exercise Physiologist

Body Composition

PhD from Australian Institute of Sport. Developed the integrated ideal weight model adopted by the fitness industry. Works with professional sports teams.

PhD Exercise PhysiologyCSCS

Calculators:

Ideal WeightWaist-to-HipLean Body MassBody Type

Why Expert Review Matters

Validated Formulas

Every calculation uses peer-reviewed methods from scientific literature.

📋

Real-World Experience

Our curators bring decades of practical experience to every recommendation.

🔒

Unbiased & Independent

No sponsorships or affiliations. Just honest, evidence-based tools.