Whetstone Tools · Catalog · 07 live

The catalog.

Seven tools, three families. Expand a family to see its tools — every plate states what the tool outputs, where its data comes from, and what it can't know.

Last updated June 12, 2026

Field calculators04 tools
No. 01 · HitchMath Calculator · Towing

Can your truck really tow that RV?

Fifth-wheel and travel-trailer payload calculators that check the number that actually decides it — your door-sticker payload, not the brochure tow rating. Pass/fail verdicts per limit, the limiting factor named, and a summary you can paste into any forum thread.

Output
Pass / Marginal / Fail per limit — payload, tow rating, GCWR, rear axle
Source
Your door-sticker numbers; pin- and tongue-weight planning factors per the published methodology
Runs
In your browser; nothing sent

Can't know: your truck's real loaded weight — a CAT-scale ticket beats every calculator, including this one.

No. 02 · Heat Pump Sizing Calculator · HVAC

What size cold-climate heat pump do you actually need?

Estimates your design-day heating load as an honest range, checks any unit's certified capacity at your design temperature (47/17/5°F rating points, conservatively interpolated), and finds right-sized cold-climate certified models from ENERGY STAR data.

Output
Design-day load range (BTU/h) + right-sized certified model matches
Source
EPA ENERGY STAR certified products list; published design temperatures
Runs
In your browser; nothing sent

Can't know: your actual insulation R-values — it gives a range, not a point.

No. 03 · Backup Power Planner Calculator · Electrical

What size generator (or battery) do you need?

Pick the appliances you must keep running; get the minimum generator size with the correct single-largest-surge math, a battery option with a real inverter-surge check, and a 20-year cost comparison — with the carbon-monoxide safety rules front and center.

Output
Minimum generator watts, battery + inverter option, 20-year cost comparison
Source
Published appliance running and surge wattages, cited in the methodology
Runs
In your browser; nothing sent

Can't know: your appliances' actual nameplate watts — check the labels; surge draw varies by model.

No. 04 · Passport Timeline Calculator · Travel

Will my passport arrive before my trip?

Enter your travel date and how you're applying; get a dated SAFE / cutting-it-close / won't-make-it verdict from the current official State Department processing and mailing times — including the four weeks of mail most checklists forget.

Output
Dated SAFE / cutting-it-close / won't-make-it verdict
Source
U.S. State Department current published processing and mailing times
Runs
In your browser; nothing sent

Can't know: your application's actual place in the queue — these are published averages, not a tracking number.

Business calculators01 tool
No. 05 · Peak Season Surcharge Calculator · Shipping

What will peak-season surcharges add to your shipping bill?

Compares the published UPS, FedEx, and USPS peak/demand surcharges week by week for your volume, service tier, and dates — and names the cheapest carrier each week. Currently the 2025-26 published schedules; 2026-27 rates land the day carriers publish.

Output
Week-by-week per-package surcharge per carrier + season total, cheapest carrier flagged
Source
USPS official press release (primary); UPS & FedEx schedules cross-verified across 3-4 sources, all cited
Runs
In your browser; nothing sent

Can't know: your negotiated contract — this compares published list surcharges only, and many contracts waive or discount them.

SEC data · Chrome extensions02 tools
No. 06 · FilingSheet Chrome extension · SEC data

SEC financials to a spreadsheet, in one click.

A free Chrome extension that pulls any US public company's numbers from SEC EDGAR and exports clean CSV — no API key, no account, nothing leaves your browser.

Format
Clean CSV (Pro adds all fiscal years, full line items, Excel)
Source
SEC EDGAR public company-facts API
Runs
In your browser; nothing leaves it

Can't know: anything EDGAR doesn't publish — if the SEC doesn't have the number, neither do we.

No. 07 · FilingScout Chrome extension · SEC data

Search the full text of every SEC filing since 2001.

Real filters, saved searches, match preview, CSV export — free, entirely in your browser.

Format
Filtered results with match preview; CSV export
Source
SEC EDGAR full-text search index (filings since 2001)
Runs
In your browser; nothing leaves it

Can't know: filings before 2001 — EDGAR's full-text coverage starts there.

On the bench

Western big-game draw odds · RV winterization — each ships when it passes the standard.