How SavvyToolz Works: Methodology, Data & Accuracy

See how SavvyToolz generates secure random values, handles time zones, calculates results, processes tool data, and documents accuracy limitations.

Secure randomness without modulo bias

The Password Generator, Random Spinner, and UUID v4 Generator draw values from the browser's crypto.getRandomValues() API. Random bounded integers use rejection sampling before modulo reduction so outcomes are not skewed when the range does not divide 2^32 evenly.

Read the W3C Web Cryptography API reference

Instants, IANA zones, and DST

Time-zone conversions format the same instant in named IANA zones and request offsets for the selected date through the browser's Intl.DateTimeFormat implementation. Daylight-saving rules, fractional-hour offsets, and browser time-zone data can affect the displayed result, so critical schedules should be confirmed with an authoritative local source.

IANA Time Zone Database · ECMA-402 Intl.DateTimeFormat

Formulas, units, and rounding

Calculator pages publish representative formulas and display rules. Adult BMI uses kg/m², or 703 × lb/in² for imperial inputs, and is an informational screening measure rather than a diagnosis. The fixed-payment loan estimate covers principal and interest and excludes taxes, fees, insurance, and lender-specific rules.

The adult BMI categories and limitations follow CDC Body Mass Index guidance. The loan explanation follows the standard amortization concept described by the Consumer Financial Protection Bureau; SavvyToolz does not produce a lender quote or payment-by-payment amortization schedule.

Unit relationships are intended to follow established SI definitions where applicable; see the NIST Guide for the Use of the International System of Units.

What stays local and what does not

Browser-local describes where the primary tool transformation occurs; it does not mean that a page makes zero network requests. The route-level disclosure identifies tool inputs, local storage, reference-data requests, runtime-asset providers, and ordinary network metadata.

View the machine-readable data-processing matrix · View its JSON Schema

External providers and purpose

Documented dependencies include reference-rate and IP information providers, browser runtime assets, analytics, and font requests. The disclosure records the purpose, trigger, fields intentionally sent or not sent, and provider documentation where available.

Known limitations and verification

Browser implementations, third-party sources, time-zone databases, floating-point arithmetic, simplified formulas, and changing provider behavior can affect results. Health, financial, legal, travel, payroll, and other consequential decisions require an appropriate authoritative source or qualified professional.

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