The Calcowa Blog
Clear, practical guides to everyday calculations and conversions. Each one is written by the team that builds the tools, with the formula shown.
Target Heart Rate Zones for Fat Loss
Target heart rate zone for fat loss runs about 60 to 70 percent of your max heart rate, but higher zones burn more total fat. Get the full chart and math.
Calories Burned Walking: A Complete Guide
Calories burned walking depends on your weight, pace, and incline. A 155-pound person burns about 86 calories per mile at a moderate pace. See the charts.
Health & FitnessWhat Is a Healthy Body Fat Percentage?
A healthy body fat percentage depends on your sex and age. See the full range charts, how to measure yours accurately, and why it beats BMI as a marker.
Health & FitnessWhat Is a Good BMI? Chart and Limits
What is a good BMI? For most adults a healthy BMI runs 18.5 to 24.9, but the number has real blind spots. See the full chart by age, sex, and body type.
Health & FitnessHow to Count Macros: Protein, Carbs, and Fat
How to count macros without the confusion: the exact protein, carb, and fat grams to eat for your goal, how to read a food label, and a no-app hand method.
Health & FitnessHow Much Protein Per Day to Build Muscle
How much protein per day do you need to build muscle? Get the exact grams by bodyweight and goal, the per-meal absorption myth, and the cheapest sources.
EducationHow to Calculate GPA on a 4.0 Scale
How to calculate GPA: multiply each grade's points by its credits, add them, then divide by total credits. Full 4.0 scale chart plus cumulative GPA math.
Health & FitnessHow to Lose Weight the Healthy Way
How to lose weight the healthy way: the pace that actually sticks, where hidden calories hide, and the weekly habits that keep the weight off after the diet.
MathHow to Calculate Percentage (with Examples)
How to calculate percentage: divide the part by the whole and multiply by 100. Get all 3 percent formulas, mental math shortcuts, and worked examples.
MathHow to Calculate Standard Deviation Step by Step
How to calculate standard deviation: find the mean, square each value's distance from it, average the squares, then take the square root. Worked examples.
ConstructionHow Much Gravel Do I Need? Coverage Chart
How much gravel do I need? A 10x10 patio base at 4 inches takes 1.23 cubic yards, about 1.7 tons. Get the formula, coverage charts, and ton conversions.
ConstructionHow Many Tiles Do I Need? (with Waste Factor)
How many tiles do I need? A 10x10 room takes 110 twelve-inch tiles with waste included. Get the formula, waste factors by layout, and box counts by size.
Health & FitnessHow Many Calories to Lose Weight? Daily Targets
How many calories to lose weight? Find your daily target by goal pace, see why the 3,500 calorie rule overpredicts, and know the safe floor before you cut.
FinanceHow Much House Can I Afford? The Real Math
How much house can I afford? Read your answer from a salary table, compare the 28/36 rule with three others, and see the real monthly cost before you buy.
ConvertersHow Many Tablespoons in a Cup? Full Chart
How many tablespoons in a cup? A US cup holds 16 tablespoons or 48 teaspoons. Get every fraction chart, butter stick math, and the awkward thirds workaround.
ConvertersHow Many mL in a Cup? US, UK and Metric
How many mL in a cup? A US cup is 237 mL, a metric cup is 250 mL, and a UK cup holds 284 mL. Get the full chart, cup-size decoder, and rounding error math.
ConstructionHow Much Concrete Do I Need? Formula and Chart
How much concrete do I need? A 10x10 slab at 4 inches takes 1.23 cubic yards, about 56 bags of 80 lb mix. Get the formula, yardage charts, and bag counts.
ConvertersHow Many Ounces in a Cup? Dry vs Liquid
How many ounces in a cup? A US cup is 8 fluid ounces, but dry ounces vary: a cup of flour weighs 4.2 oz, sugar 7.1 oz. Get the full charts and the fix.
FinanceHow to Pay Off Your Auto Loan Faster
How to pay off your auto loan faster: five strategies tested on one $28,000 loan, with tables showing how many months and how much interest each one saves.
EducationStudy Tips That Actually Work (Science-Backed)
Study tips ranked by evidence: which techniques top the research, which waste your hours, plus the weekly study-hour math nobody shows you. Charts inside.
ConvertersBaking Substitutes: Eggs, Butter, Dairy, Oil
Baking substitutes for eggs, butter, buttermilk, sour cream, heavy cream, milk, and oil, with exact ratios, gram weights, and a swap risk rating for each.
ConstructionHow Much Paint Do I Need for a Room?
How much paint do I need? Most rooms take 2 gallons for two coats of wall paint. Get the formula, gallons-by-room-size charts, and ceiling and trim math.
Health & FitnessWhat Is a Calorie Deficit for Weight Loss?
What is a calorie deficit? Eating fewer calories than you burn. Learn how to calculate yours, pick a safe deficit size, and fix stalls when loss stops.
FinanceHow to Get Out of Debt: A Realistic Plan
How to get out of debt with a plan that actually sticks: six steps, a real four-debt example, and snowball vs avalanche vs hybrid numbers side by side.
Health & FitnessHow Much Water Should You Drink a Day? A Complete Guide
How much water should you drink a day? Most adults need about 8 to 13 cups, but your weight, activity, and climate shift the number. Here's how to find yours.
FinanceHow to Pay Off Credit Card Debt Fast
How do you pay off credit card debt fast? Compare the snowball and avalanche methods with a real worked example, and see which clears your cards sooner.
Health & FitnessHow to Fall Asleep Fast: 12 Methods That Work
How to fall asleep fast: try the military method, 4-7-8 breathing, and 10 more proven tricks, plus the best sleep position and how long to nap by goal.
Date & TimeBusiness Days vs Calendar Days Explained
Business days are weekdays, not weekends or holidays. Here's how they differ from calendar days, how to count working days, and why 5 isn't a full week.
Date & TimeHow Many Days Are in a Year?
How many days are in a year? 365 in a common year and 366 in a leap year. Here's why, which years are leap years, and the days in every month, with tables.
Date & TimeHow to Calculate Days Between Two Dates
How to work out the number of days between two dates by hand or fast. The counting method, worked examples, leap years, and weeks or months between dates.
ConvertersCups to Grams: The Complete Baking Chart
A cup of flour and a cup of sugar do not weigh the same. Convert cups to grams for flour, sugar, butter, and 25+ ingredients, with fractional-cup charts.
ConvertersGrams to Cups: The Reverse Baking Chart
Got a recipe in grams but only measuring cups? Here's how to convert grams to cups for flour, sugar, butter, and 20+ ingredients, with a full reverse chart.
ConvertersHow Many Grams Are in a Cup? (Full Chart)
How many grams are in a cup? It depends on the ingredient: flour is 120g, sugar 200g, butter 227g. See the full per-ingredient chart and why it changes.
Health & FitnessBMR vs TDEE: What's the Difference?
BMR is what you burn at rest; TDEE is your full daily burn. Here's the difference, the activity multipliers, and how to use each one for your weight goals.
Health & FitnessWhat Is BMR? Basal Metabolic Rate Explained
BMR is the calories your body burns at rest. Here's what basal metabolic rate means, the normal range, what affects it, and how to use it for your goals.
Health & FitnessHow to Calculate BMR (Mifflin-St Jeor Formula)
Learn how to calculate your BMR by hand with the Mifflin-St Jeor formula, plus Harris-Benedict and Katch-McArdle, with worked examples for men and women.
FinanceHow Much to Tip Your Hairdresser (2026)
How much should you tip a hairdresser? The standard is 15 to 20 percent. Here's what to tip for cuts, color, the salon owner, assistants, and cash vs card.
FinanceHow to Calculate a Tip (Fast Mental Math)
How to calculate a tip in your head in seconds. The easy 10-and-double trick for 20%, a full tip chart for 15/18/20%, and how to split it between people.
FinanceHow Much to Tip: The Complete 2026 Guide
How much should you tip? Here's the 2026 tipping guide for restaurants, hairdressers, movers, delivery, taxis, and more, with a full percentage chart.