Flat vs Reducing Rate: How EMI Really Works
Why two loan quotes with the same headline rate can cost very different amounts: how flat and reducing-balance rates convert, where each EMI goes, and what prepaying changes.
Related tool: EMI Calculator
Guides
Practical guides for the questions behind the tools: what makes a file large, how a calculation actually works, why a parser rejects your input. Each guide leads to the tool that does the job, and each area below also lists the everyday problems and the tool for each.
Finance
How loan, savings and tax calculations actually work: the formulas, what each calculator assumes, and where real products differ. Evergreen mechanics only; nothing here recommends a product or a rate.
SIP Projections Explained: What Is Assumed
What a SIP projection assumes (a constant return, payment timing, no costs), how nominal and effective rates differ, and why real returns move around.
Related tool: SIP Calculator
GST Calculations Explained: Inclusive vs Exclusive
Adding and removing GST correctly, the common mistake with inclusive prices, and when the tax splits into CGST and SGST versus IGST.
Related tool: GST Calculator
Compound vs Simple Interest and the Rule of 72
How simple and compound interest differ, why compounding frequency and the effective rate matter, and how far the Rule of 72 can be trusted.
Related tool: Compound Interest Calculator
Compounding Frequency Compared: Annual to Daily
Worked examples of how much the compounding frequency changes a balance, why the gain flattens out, and when it matters more than it looks.
Related tool: Compound Interest Calculator
How Much to Save for Retirement: Key Inputs
The inputs a retirement projection needs, what it assumes, and how much the answer moves when return, inflation, savings rate and retirement age change.
Related tool: Retirement Savings Calculator
How Lenders Size a Mortgage: DTI, Rate, Term
How debt-to-income limits turn your income into a maximum payment, and how rate, term, existing debts and down payment change the loan you can get.
Related tool: Mortgage Affordability Calculator
FD vs RD vs PPF: How Each Compounds
How each of the three compounds and gets its rate, and what the calculators simplify. A comparison of mechanics, not a ranking.
Related tool: FD Calculator
Common problems, and the tool for each
- What will my monthly loan payment be?EMI Calculator
- Home loan with property tax and insuranceMortgage Calculator
- How large a loan does my income support?Loan Affordability Calculator
- What will regular monthly investing grow to?SIP Calculator
- Growth of a lump sum with interestCompound Interest Calculator
- Fixed deposit, recurring deposit or PPF maturityFD Calculator
- Price with or without GSTGST Calculator
PDF & Documents
The practical problems behind PDF work: files that are too large to upload, scans you can't copy text from, pages that need to be combined or converted.
How to Compress a PDF Without Losing Quality
What actually makes a PDF large, and how to shrink it while keeping text and images looking right.
Related tool: Compress PDF
How to Convert PDF to Word (And When It Won't Come Out Perfect)
What PDF-to-Word conversion can and can't reliably recover, and how to get the cleanest result.
Related tool: PDF to Word Converter
How to Merge Multiple PDF Files Into One
Combining PDFs in the right order, handling password-protected files, and keeping quality intact.
Related tool: Merge PDF Files
How to Get a PDF Under 200 KB, 1 MB or 2 MB
A step-by-step order for getting a PDF under a portal's size limit, what sets the minimum size, and what to do when compression alone isn't enough.
Related tool: Compress PDF
Scanned vs Text PDFs and How OCR Accuracy Works
How to tell a text PDF from a scanned one, which tool fits each, and what decides how accurate OCR is.
Related tool: Scanned PDF to Text (OCR)
Common problems, and the tool for each
- PDF too large to uploadCompress PDF
- Several files that should be one documentMerge PDF Files
- Only some pages are neededSplit / Extract PDF Pages
- Need to edit the content in WordPDF to Word Converter
- Can't select or copy the textPDF to Text Converter
- Photos or scans that should become a PDFImage to PDF Converter
- PDF pages as picturesPDF to Image Converter
Images
Getting an image into the right size, format and file weight, and getting text back out of one.
PNG vs JPG vs WebP: Which Image Format Should You Actually Use?
A plain-language breakdown of when each format genuinely wins, not just a spec-sheet comparison.
Related tool: Image Format Converter
How to Reduce a Photo's File Size
Why resizing usually saves more than the quality slider, and the order that gets a photo under a KB limit while staying readable.
Related tool: Image Compressor
Common problems, and the tool for each
- Photo too large in KBImage Compressor
- Wrong pixel dimensionsResize Image
- Wrong format for the jobImage Format Converter
- Text trapped inside a pictureImage to Text (OCR)
- Location and camera data in a photoEXIF Data Remover
Developer
The errors and edge cases developers hit with JSON, tokens, encodings, hashes and timestamps, with the reasoning behind each rather than just the fix.
JSON Parse Errors: Common Mistakes and Fixes
The mistakes behind most "invalid JSON" errors, with before-and-after fixes and how to read where the parser gave up.
Related tool: JSON Formatter & Validator
How JWTs Work: Header, Payload, Signature
What the three parts of a JWT hold, what decoding does and doesn't prove, and how to read expiry claims safely.
Related tool: JWT Decoder
Unix Timestamps and Time Zones: Seconds vs ms
Seconds versus milliseconds, UTC versus local time, and the year 2038 limit, plus the mistakes that produce wrong dates.
Related tool: Unix Timestamp Converter
Base64 Explained: Why It's 33% Larger
How Base64 works, why it adds about a third to the size, why it isn't encryption, and how Base64URL differs.
Related tool: Base64 Encoder & Decoder
Common problems, and the tool for each
- JSON that won't parseJSON Formatter & Validator
- What is inside this JWT?JWT Decoder
- A Unix timestamp that looks wrongUnix Timestamp Converter
- Encoding data as textBase64 Encoder & Decoder
- Escaping a value for a URLURL Encoder & Decoder
- Checking a file or string with a hashHash Generator