Skip to main content

Guides & how-tos

Practical answers with the math shown — every guide pairs with a free calculator. Written by Mohamed Zakrya.

Health & Fitness

How Much Water Should You Drink a Day? Real Numbers, Not the 8-Glass Myth

A baseline from your body weight, two flat top-ups for activity and heat — and why the eight-glass rule is one specific person's answer.

July 23, 2026 · 13 min read

Health & Fitness

How to Calculate Body Fat Percentage: Tape-Measure Math That Works

Three tape measurements, one logarithmic formula, a neutral reference band — and why the free method holds up against a lab scan.

July 23, 2026 · 12 min read

Finance & Math

How to Calculate Take-Home Pay: From Gross to What You Keep

One combined deduction rate, your pay schedule, and a two-minute pay stub calibration — gross to net in two lines of math.

July 23, 2026 · 13 min read

Health & Fitness

What Is TDEE? Total Daily Energy Expenditure, With Real Numbers

The resting floor, the activity multiplier that scales it, and how to read the maintenance number that comes out.

July 23, 2026 · 13 min read

Electricity & Energy

What Size Generator Do I Need? Wattage by Scenario

Running watts plus one surge, times 1.2. The honest tally that gets it right, and the mistake that stalls a generator the moment the compressor kicks in.

July 23, 2026 · 13 min read

Finance & Math

How Does Compound Interest Work? The Math That Grows Money

Interest that earns interest — the formula, the frequency gap, and why steady deposits and time do most of the work.

July 20, 2026 · 7 min read

Home Improvement

How Many Rolls of Wallpaper Do I Need? Pattern Repeat Math

The wall-area takeoff, the usable yield of a roll, and why the pattern repeat decides your order.

July 20, 2026 · 6 min read

Home Improvement

How Many Tiles Do I Need? Sizes, Waste & Boxes

The formula, the waste allowance that actually fits your layout, and how to turn a tile count into whole boxes.

July 20, 2026 · 7 min read

Electricity & Energy

How Much Does Electricity Cost? Reading Your Bill in kWh

The kWh formula, the rate your bill actually charges, and what a heater, an always-on device, and standby power really cost.

July 20, 2026 · 6 min read

Home Improvement

How Much Drywall Do I Need? Sheets, Mud & Screws

The area formula with the standard opening deductions, the sheet-size trade-off, and the mud, tape and screw counts that go with it.

July 20, 2026 · 6 min read

Home Improvement

How Much Fencing Do I Need? Posts, Panels & Gates

One section count drives the whole bill of materials — posts, panels, gates, and the concrete nobody tallies before the store run.

July 20, 2026 · 7 min read

Health & Fitness

What Is My BMR? Basal Metabolic Rate, Explained With Numbers

The Mifflin-St Jeor equation, what each input is worth, and why BMR is the floor of your calorie needs — never the budget.

July 20, 2026 · 6 min read

Home Improvement

What Size Air Conditioner Do I Need? BTU by Room Size

Floor area gives you the base number. Ceiling height, sun, bodies and a kitchen decide whether you buy that unit or the next one up.

July 20, 2026 · 7 min read

Home Improvement

How Much Gravel Do I Need? Driveways, Paths & Drainage

The volume formula, the tons conversion, and the right depth and stone for every job.

June 20, 2026 · 7 min read

Home Improvement

How Much Topsoil Do I Need? Lawns, Beds & Topdressing

The volume formula, the right depth for each job, and how topsoil differs from garden soil, compost, and fill dirt.

June 20, 2026 · 7 min read

Home Improvement

How Much Concrete Do I Need? Slab Math, Bag Counts, and When to Call the Truck

Yards and bag counts for real projects — patios, shed slabs, and deck piers — with the ordering math nobody tells you.

June 20, 2026 · 6 min read

Home Improvement

How Much Mulch Do I Need? Bed-by-Bed Math in Yards and Bags

Real numbers for straight beds, curved borders, and tree rings — plus which mulch to actually buy.

June 20, 2026 · 7 min read

Home Improvement

How to Pest-Proof Your Home Before Vacation

Cut off food, moisture, and entry points before you leave — so you come home to your house, not to ants, mice, or pantry moths.

June 16, 2026 · 7 min read

Black Heart Emoji 🖤 Meaning: Texting, Snapchat & How to Use It

The black heart is the moodiest emoji in the keyboard — it can mean dark humour, grief, edgy affection, or solidarity. One thing it almost never means: hate. Here's how to read 🖤.

June 14, 2026 · 6 min read

Blue Heart Emoji 💙 Meaning: Texting, Snapchat & How to Use It

The blue heart is the calm, loyal, 'I've got your back' heart — trust and friendship more than romance. Here's how to read 💙 in texts, including the friend-zone question, and across every app.

June 14, 2026 · 6 min read