Car Seat Fit Checker – Online Height/Weight vs. Seat Limits
Enter child's stats and compare to typical rear-facing, forward-facing, and booster seat requirements. Reference tool.
UD5 Toolkit
Answer a few quick questions to check if you may be eligible to donate blood.
Enter child's stats and compare to typical rear-facing, forward-facing, and booster seat requirements. Reference tool.
Enter your UK tax code and see an explanation of what the numbers and letters mean. Simple educational reference. No data stored.
Measure your waist‑to‑hip ratio and learn about associated health risks. WHR interpretation. Educational only.
Evaluate the strength of your passwords with a visual meter and detailed feedback. Check for length, complexity, and breached passwords. All analysis is client-side.
Check your Body Mass Index using standard or metric units. Get a health category analysis instantly. Educational purpose only; data stays private.
Determine the minimum sample size needed for a survey or A/B test with a given confidence level and margin of error.
Enter baby's weight in lbs or kg to see suggested diaper sizes across major brands. General reference, no data collected.
Enter your bird species and weight to find the correct harness size. Visual adjustment guide.
Log daily sleep to see cumulative sleep debt or surplus over weeks. Visualizes chronic sleep loss trends. Stores data locally in your browser only.
Select month and get a to‑do list (clean gutters, check weatherstripping). Local storage, printable.
See your current notification permission status. Request or reset it. Test browser notification behavior.
Enter an API URL and quickly check its HTTP status code and response time. See response headers and body. Browser fetch.
Reference for standard blanket and afghan sizes in inches and cm. Perfect for knitters and crocheters.
Create a printable bingo card filled with self‑care activities. Relax, exercise, hydrate. Tick them off.
Calculate BMI for children and teens (ages 2‑19) and see the percentile based on CDC growth charts. Educational only.
Calculate infant weight, length, and head circumference percentiles using WHO and CDC reference data. Visual growth chart and interpretation for parents.
Plot your child's height and weight on WHO growth charts over time. Data saved locally for privacy. Visualise growth trajectory.
Estimate bulb mode exposure time needed for different light sources and distances. Experimental photography aid.
Enter number of children and see estimated cups, plates, party favors needed. Quick planning tool for birthday parties.
Estimate ovulation day and fertility window from last menstrual period. Displays probable conception dates. Informational only; processes locally in browser.
Use your device microphone to measure approximate sound pressure level in dB. Not calibrated, for rough reference. Local only.
Enter wallet size and get the exact length of duct tape strips needed to build a sheet. DIY crafting.
Count words, characters, sentences, and paragraphs instantly. Analyze text density and reading time. Secure client-side processing for your content privacy.
Approximate monthly child support obligation based on both parents incomes and number of children. Uses simplified model for educational reference. Not legal advice.
Compare options two at a time and get a final ranking. Systematic way to choose a vacation spot or project.
Understand teething order, typical symptoms, and safe relief methods. Charts and tips for new parents. Educational, not medical advice.
A digital sticker board where kids can place virtual stickers for completed chores or goals. Encourages positive behavior with no paper waste.
Enter desired pom-pom diameter to estimate yards needed and number of wraps. Quick craft math.
Enter head circumference to get crown diameter and length. Perfect fit top‑down hats.
Compare renting to buying a home by entering price, rent, interest, and years. See which saves more. Simplified model.