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The math you need, without the mess.
Fast calculators with transparent formulas. Lightweight pages with respectful ads to keep the site free.
📚 Attendance 75% Calculator
Calculate how many classes you need to attend to reach your target percentage.
⚡ EV Charging Time
Estimate how long it takes to charge your electric vehicle.
📊 Percentage Calculator
Quick percentage calculations: A% of B, increases, decreases, and more.
🔢 Fraction Simplifier
Reduce fractions to lowest terms with mixed number and decimal.
⚖️ Ratio & Proportion
Simplify ratios and solve proportions easily.
🔧 LCM & GCD
Find the least common multiple and greatest common divisor.
📈 Average & Median
Calculate mean, median, mode, and summary statistics.
📝 Blog
Helpful guides and examples for using our calculators.
75% Attendance Calculator Education
Enter total classes held so far, the number you attended, and your target percentage.
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Your current percentage and classes needed will appear here.
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How it works
Current % = (Attended / Held) × 100
Classes to reach target (assuming you attend all upcoming):
x ≥ (T·H − A) / (1 − T), where T is target as a decimal (e.g., 0.75).
Show an example
If H=60, A=40, T=75% → T=0.75 → x ≥ (0.75×60 − 40) / (1 − 0.75) = (45 − 40)/0.25 = 20. You need 20 classes in a row.
FAQs
What if I already have ≥ target?
You need 0 classes; we also show how many you can miss and still stay above target.
What if target is 100%?
That's only possible if you never missed a class; otherwise it's unattainable.
EV Charging Time Calculator Energy
Estimate how long it takes to charge your EV at home or a public charger.
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Estimated time appears here.
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How it works
Energy needed (kWh) = Capacity × (Target − Start)/100.
Accounting for loss (heat/charging overhead): add Loss% to energy.
Time (hours) = Energy / Charger kW.
Show an example
60 kWh battery, 20%→80%, charger 7.2 kW, 10% loss: needed = 60×0.6 = 36 kWh; +10% = 39.6 kWh; time = 39.6/7.2 ≈ 5.5 h → 5h 30m.
FAQs
Why is DC fast slower above 80%?
Charge curves taper; this simple estimate assumes flat power. Use it for planning, not exact timing.
What loss should I use?
Typical 7–12% at AC home charging; set 0% if you don't want to account for it.
Percentage Calculator General
Do quick percent math: A% of B, what percent A is of B, increase/decrease by %, and percentage change.
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Result and formula will appear here.
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How it works
A% of B: (A/100) × B
A as % of B: (A/B) × 100
Increase B by A%: B × (1 + A/100)
Decrease B by A%: B × (1 − A/100)
% Change from A to B: ((B − A)/A) × 100
Example
A=20, B=150 → A% of B = (20/100)×150 = 30. Increase by A% = 150×1.2 = 180.
FAQs
What if B is 0?
"A as % of B" is undefined; we'll show a helpful message.
Do you round?
We display up to two decimals for readability.
Fraction Simplifier General
Reduce any fraction to lowest terms; see mixed number and decimal.
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Simplified fraction, mixed number, and decimal will appear here.
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How it works
Lowest terms = divide top & bottom by the GCD (greatest common divisor). Mixed number shows whole part + remainder.
Example
42/56 → GCD=14 → 3/4 = 0.75
Ratio / Proportion Calculator General
Simplify ratios and solve simple proportions like a:b = c:x.
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Result and formula will appear here.
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How it works
Simplify: divide both sides by GCD(a,b).
Proportion: a:b = c:x → x = (b×c)/a.
Check equality: a:b = c:d via cross-multiplication: a×d = b×c.
LCM & GCD Calculator General
Enter numbers (comma-separated). We'll compute GCD and LCM.
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GCD and LCM will appear here.
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How it works
GCD via Euclid's algorithm. LCM(a,b) = |a×b| / GCD(a,b). For more than two numbers, reduce pairwise.
Example
12, 18, 30 → GCD=6, LCM=180
Average / Median / Mode Calculator General
Paste numbers (comma or space separated). We'll show mean, median, mode, sum, min, max, count.
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Summary stats will appear here.
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How it works
Mean = sum / count. Median = middle after sorting. Mode = most frequent value(s). We also show basics: sum, min, max.
Example
10, 12, 15, 19, 19, 21 → Mean=16, Median=17, Mode=19
Blog Guides
Short, helpful articles that link directly to our calculators and explain the math.
About EasyMathTools
Free, fast calculators that show the formula and a worked example. Built to be lightweight and accessible so results are instant even on slow networks.
We respect your privacy and use only essential client-side code—no logins, no tracking beyond standard analytics. All calculations happen in your browser.
Coming next: UPS/Inverter Runtime, Quilt Binding Yardage, CGPA ↔ Percentage.
Privacy Policy
We don't collect personal information. Calculations run entirely in your browser. We may use basic analytics (e.g., Google Analytics or Plausible) to understand page traffic.
If we use Google AdSense, cookies may be used to serve ads based on your visits to this and other websites. You can opt out of personalized advertising by visiting Google's Ad Settings.
Contact us for any privacy questions at support@easymathstools.com.
Terms of Use
EasyMathTools is provided "as is" without warranties of any kind. Calculations are for informational purposes only; verify results for high-stakes use. By using this site, you agree not to misuse or attempt to disrupt the service.
We may update these terms from time to time. Continued use constitutes acceptance of the updated terms.
Contact
Email: support@easymathstools.com
If you represent a school or publisher and want to embed a calculator, we can provide a lightweight script snippet.