BEng Civil Engineering; 8 years in project management.

Marcus Laurent

Contributor, Construction & Everyday Life

0 calculators 0 articles Member since Jun 2026

About

Marcus focuses on the "practical math" calculators: home projects, construction, fuel, and travel. His goal is simple — give the reader a number they can actually use on site or on the road in under 30 seconds.

Before writing full-time, he spent eight years in infrastructure and residential construction project management.

Areas of expertise

Construction math Home projects Travel planning Fuel economy

Education & credentials

BEng Civil Engineering — Polytechnique Montréal

Sports

Badminton Smash Shuttle Speed Calculator

Estimates the shuttle speed after a badminton smash from racket head speed and typical energy transfer coefficient.

basic

7,031 4.3 1 min

Finance

Safety Stock from Demand Variability and Lead Time Calculator

Calculates safety stock = z × σ_demand × √LT, where z is the service-level z-score (e.g., 1.65 for 95%), σ_demand is the...

basic

18,716 4.4 1 min

Physics

Blackbody Radiant Intensity at a Given Wavelength Calculator

Calculates the Planck spectral radiance B(λ,T) = (2hc²/λ⁵) / (exp(hc/λkT) − 1) in W/(m²·sr·m). Uses h = 6.626×10⁻³⁴ J·s,...

basic

10,239 4.4 1 min

Construction / Materials

Tile Calculator

Work out tile count and boxes needed with an adjustable waste factor.

basic

18,797 4.7 1 min

Sports

Tennis Break Point Conversion Rate Calculator

Calculates break point conversion percentage in tennis from break points won and break points faced.

basic

17,063 3.9 1 min

Health

Wells DVT Clinical Prediction Rule Calculator

Calculates the Wells DVT score to stratify pretest probability of deep vein thrombosis and guide D-dimer testing or ultr...

basic

12,942 4.9 1 min

Sports / Cycling

Energy Expenditure from Cycling Power and Duration Calculator

Calculates energy expenditure: kJ = power(W) × duration(s) / 1000. At ~22% efficiency, kcal ≈ kJ × (1/4.184) / 0.22 = kJ...

basic

19,847 3.9 1 min

Health

Daily Caloric Needs from BMR and Activity Level Calculator

Estimates total daily energy expenditure TDEE = BMR × PAL, where PAL is the physical activity level multiplier: sedentar...

basic

6,067 3.9 1 min

Math / Percentage

Gamma Function via Stirling Approximation Calculator

Approximates the gamma function Γ(z) using Stirling's series for z > 0: Γ(z) ≈ √(2π/z) · (z/e)^z. For integer z, Γ(n) =...

basic

3,580 4.6 1 min

Health

Kidney GFR Creatinine Clearance Calculator

Estimates creatinine clearance (CrCl) using the Cockcroft-Gault formula to assess kidney function for drug dosing adjust...

basic

1,478 3.9 1 min

Construction / Materials

Fence Calculator

Estimate the number of posts, rails, and panels needed to build a straight fence of any length and post spacing.

basic

8,697 4.3 1 min

Physics

Thin Lens Focal Length and Image Magnification Calculator

Applies the thin lens equation 1/f = 1/d_o + 1/d_i to find image distance and magnification m = −d_i/d_o. Also indicates...

basic

24,203 4.4 1 min

Showing 25 to 36 of 386 results

guide Conversions

Unit Conversion Without Typos: A Field Guide

Most unit-conversion mistakes are dumb mistakes — swapped factors, dropped decimals, wrong direction. A short guide to not making them.

Marcus Laurent

May 14, 2026 3 min

tutorial Fitness

Running Pace: How to Read Splits Without Getting Lost

Pace, splits, and goal times talk about the same thing from three different angles. A short guide to keeping them straight mid-race.

Marcus Laurent

Jan 24, 2026 3 min

Best Free Calculator

Browse categories

Marcus Laurent

Badminton Smash Shuttle Speed Calculator

Safety Stock from Demand Variability and Lead Time Calculator

Blackbody Radiant Intensity at a Given Wavelength Calculator

Tile Calculator

Tennis Break Point Conversion Rate Calculator

Wells DVT Clinical Prediction Rule Calculator

Energy Expenditure from Cycling Power and Duration Calculator

Daily Caloric Needs from BMR and Activity Level Calculator

Gamma Function via Stirling Approximation Calculator

Kidney GFR Creatinine Clearance Calculator

Fence Calculator

Thin Lens Focal Length and Image Magnification Calculator

Unit Conversion Without Typos: A Field Guide

Running Pace: How to Read Splits Without Getting Lost