Daniel Oh
Featured contributor MSc Applied Statistics; 7 years in analytics and data tooling.

Daniel Oh

Senior Contributor, Math & Statistics

0 calculators 0 articles Member since Jun 2026
Biology / Microbiology

DNA Concentration Calculator

Compute DNA concentration in ng/μL from a spectrophotometer absorbance reading at 260 nm and the cuvette dilution factor...

basic
3,565 4.9 1 min
Other

Cat Years Calculator

Estimate the human-equivalent age of a cat using the standard veterinary mapping (15 + 9 + 4 per year afterwards).

basic
12,692 4.8 1 min
Math / Geometry

Polar to Cartesian Converter

Convert a polar coordinate (r, θ) into the Cartesian coordinate (x, y) = (r cos θ, r sin θ), with θ entered in degrees.

basic
22,546 4.9 1 min
tutorial Math

Percentages Without the Headache

Every "X% of Y" problem, every "what percent of", every percent-change question — written out the way you'd actually say them.

Daniel Oh Daniel Oh
3 min

Reviewed by Daniel Oh

These calculators were technically reviewed by Daniel Oh for accuracy.