The workbench.

Two kinds of work live here. Instruments built for this site’s own production run in your browser and follow the same design language as everything else on it. Standalone apps such as Benthic carry their own design, download and updates. New work arrives as the writing needs it.

The workbench

What the calculators make

NRR waterfall Rule of 40 frontier Break-even loss 44%50%42%-6%
Synthetic example: each calculator’s first worked example, computed at build with its own arithmetic. Brass: that example in each.
Instruments
Nine, running in your browser
Standalone app
Benthic, for macOS
Terms
No account, no upload, no tracking of what you feed it

InstrumentsHouse design, in the browser. Size follows weight.

Built for this site’s work, running in your browser.

Enterprise valuation · By request

CAC & Cash Calendar Diagnostic

Multi-cohort sensitivity analysis, 24-month cash recovery calendars, counterfactual displacement breakdown, and a downloadable executive PDF report.

Open Enterprise Diagnostic

Unit economics

CAC boundary calculator

Calculate assigned CAC, incremental CAC, payback and matched LTV ratios while keeping the customer event, cohort and cost boundary visible. Includes instant PNG/SVG exhibit export.

Open the calculator

Retention & cohorts

NRR & Growth Waterfall

Model Net Revenue Retention, Gross Revenue Retention, and the SaaS Quick Ratio with live interactive waterfall decomposition and cohort expansion boundaries.

Open the planner

Capital efficiency

Rule of 40 Analyser

Analyse the trade-off between software revenue growth and profit margins with interactive 2D frontier plotting and sensitivity matrices.

Open the analyser

Pricing & margins

B2B Price Elasticity Simulator

Calculate tolerable customer churn, break-even thresholds, and gross profit deltas for B2B price changes with live interactive elasticity curves.

Open the simulator

Files & privacy

File Studio

A private workspace for resizing, converting and preparing images and PDFs to share. The browser-first image and PDF editors keep source files local.

Open File Studio

PDFs & privacy

PDF Studio

Merge, split, reorder, rotate and remove PDF pages in a private browser-first workspace.

Open PDF Studio

Documents & privacy

Document Studio

Open DOCX or text files, make basic structural edits and export a clean working copy without sending the source to a server.

Open Document Studio

Imagery

Duotone studio

Maps a photograph into a two-colour ramp: forest, ink, brass, paper, and exports lossless PNG or size-reported WebP. Runs entirely in the browser; nothing uploads.

Open the studio

Standalone appA separate product on its own subdomain.

Its own design, its own download and updates.

benthic.isoglu.comBenthic keeps its own look inside this frame; nothing of it reaches the rest of the site.

Benthic

For macOS

Check every reference, before you cite it.

Benthic checks reference lists from language models for invented, misattributed and retracted sources and fetches the real papers from open-access sources.

Discover Benthic Free and open source

On this bench

Everything on this bench is free to use and carries no account, no upload and no tracking of what you feed it. If an instrument here saves you an afternoon, the journal is where its thinking comes from.

Contact

Bring the question you're working on.

Research, a guest lecture, or a commercial question.