Free Online Calculators & Smart Tools
Toolz-Hub is your home for fast, accurate, and completely free online calculators. From GPA calculators and grade converters for students to pet age tools and health calculators — every tool works instantly on any device.
🎓 GPA & Grade Calculators
Our most popular tools, built for students, parents, and teachers. Calculate semester or cumulative GPA, work without credit hours, and understand exactly what your GPA means on the standard 4.0 scale.
GPA Calculator
Calculate your GPA instantly from grades and credits — weighted or unweighted.
Calculate GPA →GPA Calculator Without Credits
No credit hours? Find your GPA using letter grades alone in seconds.
Try It →College GPA Calculator
Track your semester and cumulative college GPA with credit hours.
Calculate →High School GPA Calculator
Weighted and unweighted GPA for regular, honors, and AP classes.
Calculate →Middle School GPA Calculator
Simple GPA tracking made easy for middle school students.
Calculate →Cumulative GPA Calculator
Combine multiple semesters or years into one overall GPA.
Calculate →Weighted to Unweighted GPA
Convert your weighted GPA back to the standard 4.0 scale.
Convert →GPA Scale Guide
What does your GPA actually mean? Every value from 0.0 to 4.0 explained with letter grades and percentages.
See the Full Scale →🔄 GPA & Percentage Converters
Switch between grading systems in one click — perfect for international students, applications, and transcripts.
GPA to Percentage
Convert your 4.0-scale GPA into an accurate percentage instantly.
Convert →Percentage to GPA
Turn your marks percentage into GPA on the 4.0 scale.
Convert →GPA Converter & Calculator
All-in-one converter between GPA, letter grades, and percentages.
Convert →Marks Percentage Calculator
Calculate your exam percentage from obtained and total marks.
Calculate →🐾 Pet Calculators
Understand your furry friend better with calculators built on veterinary aging and growth guidelines.
Dog Age Calculator
Convert your dog’s age to human years — breed-size aware.
Calculate →Cat Age Calculator
Find out how old your cat really is in human years.
Calculate →Puppy Weight Calculator
Estimate your puppy’s full-grown adult weight by breed and age.
Estimate →Dog Size Calculator
Predict how big your dog will get before they’re fully grown.
Predict →❤️ Health & Fun Tools
Quick calculators for fitness goals, style choices, and a bit of fun with friends.
Target Heart Rate Calculator
Find your optimal heart rate zones using the Karvonen formula.
Calculate →Face Shape Calculator
Discover your face shape for hairstyles and glasses that suit you.
Find Out →Love Calculator
Enter two names and get a fun compatibility score to share.
Test It →Female Delusion Calculator
A satirical reality-check of dating standards against real statistics.
Check It →Why Students & Pet Parents Trust Toolz-Hub
✅ Accurate Formulas
Our GPA tools follow the standard U.S. 4.0 grading scale used by most schools and colleges, and every calculator is tested against real examples. Read our testing and grading standards.
⚡ Instant Results
No signup, no email, no waiting. Every tool runs directly in your browser and gives results the moment you enter your numbers.
🔒 Private by Design
Your grades, marks, and personal details never leave your device. We don’t store or collect any data you enter into our calculators.
📱 Works Everywhere
Every calculator is fully responsive — use it on your phone between classes or on your laptop while planning your semester.
Free Online Calculators for School, Pets & Everyday Life
Toolz-Hub started with one simple goal: make the calculators students actually need free, fast, and easy to use. Our flagship GPA calculator handles weighted and unweighted grades with credit hours, while the GPA calculator without credits is perfect when all your classes carry equal weight. Whether you’re in middle school, high school, or college, there’s a calculator built for exactly how your school grades.
Numbers only tell half the story, though. Our GPA scale guide explains what every GPA from 0.0 to 4.0 actually means — which letter grade it maps to, what percentage it represents, and how competitive it is for college admissions. If you’re applying abroad or converting between systems, the GPA to percentage and percentage to GPA converters handle the math in one click.
Beyond the classroom, Toolz-Hub covers everyday questions too. Pet parents use our dog age and cat age calculators to translate pet years into human years using veterinary guidelines, and the target heart rate calculator helps you train in the right zone for your fitness goals. Every tool is free, works on any device, and never asks you to sign up. Have a question or a tool request? Get in touch — we build new calculators based on what users ask for.
❓ Frequently Asked Questions
Are all the tools on Toolz-Hub really free?
Yes — every calculator on Toolz-Hub is 100% free with no hidden charges, premium plans, or subscription fees. You never need to create an account or share your email.
How do I calculate my GPA?
Convert each letter grade to its point value on the 4.0 scale (A = 4.0, B = 3.0, C = 2.0, D = 1.0), multiply each by the course’s credit hours, add them up, and divide by total credits. Or skip the math entirely — our GPA calculator does it instantly.
Can I calculate my GPA without credit hours?
Yes. If all your classes carry equal weight, you can simply average your grade points. Our GPA calculator without credits is built exactly for this.
What is a good GPA?
A 3.0 GPA (B average) is generally considered solid, a 3.5+ is strong for competitive colleges, and a 3.7+ puts you in range for highly selective schools. See our GPA scale guide for a full breakdown of every GPA value.
How accurate are the GPA calculators?
Our tools follow the standard U.S. 4.0 grading scale used by most high schools and colleges, and we test every calculator against worked examples. Individual schools can have their own policies (like A+ weighting), so always treat your registrar’s calculation as official.
How do I convert my GPA to a percentage?
On the standard scale, a 4.0 GPA roughly equals 93–100% and a 3.0 roughly equals 83–86%, but the mapping isn’t perfectly linear. Use our GPA to percentage calculator for an accurate conversion.
How accurate are the pet age calculators?
The dog and cat age calculators follow veterinary aging guidelines rather than the outdated “multiply by 7” myth — dogs and cats age faster in their first two years, then more slowly, and our tools account for that.
Do the calculators store my data?
No. Everything you enter is processed in your browser and never sent to our servers. We don’t collect grades, marks, names, or any personal information from our tools.
Can I use Toolz-Hub on my phone?
Absolutely — every tool is fully responsive and optimized for phones, tablets, and desktops. No app download needed.
Do you add new calculators?
Yes, we regularly build new tools based on user requests. If there’s a calculator you’d like to see, contact us and tell us what you need.