The PctZen Editorial Desk

Editorial · PctZen

PctZen is a percentage calculator maintained by a small in-house group that also writes its articles — the same hands on the tool and on the page.

The subject matter is deliberately narrow — Percentage Calculator. Because it answers percent-of, what-percent, and percent-change questions instantly, with a discount and tip mode, the articles can go a level deeper than a general overview, whether the reader arrives from working out a sale price, splitting a tip or checking a percentage change between two figures.

Every article is re-read before it ships for two things — that the method holds up, and that it does not present itself as advice. Anything in a regulated area is confined to the calculation.

The contact address for corrections, support@pctzen.com, reaches the same team that writes the articles.

Recent articles

Determining Original Price From Sale Price and Discount Percentage Alone

If you know the sale price and the discount percentage, divide the sale price by (1 − discount percentage as a decimal). That's it. A $60 item marked down 25%? Divide 60 by 0.75. Original price: $80.

Reverse Percentage Math: Handling Stacked Coupons and Sales Tax Simultaneously

You're staring at a receipt. The final total reads $73.56. You know the customer walked in with two stacked coupons — 15% off, then an additional 10% off — and your jurisdiction charges 7.5% sales tax.

Calculating Percentage Difference Between Consecutive Monthly Utility Bills

Here's a mistake I see constantly: someone opens their January electric bill, sees $142, then opens February's bill and sees $168.

Proportional Recipe Adjustments: Scaling Ingredient Quantities by Serving Size Percentages

The "Just Add a Little Extra" Trap You're cooking dinner for 9. Your go-to braised short ribs recipe serves 6. So you think: "I'll just add about half again as much of everything."

The Scale Paradox: Why Body Fat Percentage Increases During Total Weight Loss

Step on the scale. Watch the number drop. Feel the rush. Now pull up your body fat percentage calculator. Watch that number climb. Feel the confusion. This is the Scale Paradox.

RFM vs Absolute Fat Loss: Decoding Relative Fat Mass Index Changes During Weight Loss

Strip away the fitness influencers and the supplement ads, and this is the question that matters when you're tracking body composition. You stepped on the scale. The number went down.

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