---
title: "Tenon Calc — pay-once construction calculator"
description: "A pay-once construction calculator: feet-inch-fraction to 1/64, thirteen calculators, any result exported as a branded PDF quote. $19.99, no ads."
canonical_url: "https://tenon.tools/calc/"
language: "en"
date_published: "2026-08-18"
last_updated: "2026-08-20"
source: "Tenon Tools"
---

# Tenon Calc

_Published: 2026-08-18_

_A construction calculator you buy once — and the only one that turns a calculation into a quote your client can sign._

> Tenon Calc is a construction calculator for iOS and Android. Thirteen calculators sit on one screen, from a feet-inch-fraction tape that works to 1/64 of an inch through rafters, stairs, concrete, drywall, studs, masonry, board feet and tile. Any result can be dropped into a quote as a line item, and the quote leaves the app as a branded PDF with your business name and your logo on it. Everything runs on the device — no account, no login, no connection required. Four calculators are free forever with no ads and no limits. $19.99 once, or 19,99 € once, unlocks the other nine, the PDF quote export and saved quotes. There is no subscription of any kind. The app is not released yet; this page describes what version 1.0 does.

## At a glance

- **Pay once, own it forever** — One payment unlocks everything, permanently. No monthly plan, no annual plan, no feature that expires and no tier that gets taken away in an update three years from now.
- **Any calculation becomes a quote** — Add results to a quote as line items, set quantities and prices, and export a PDF carrying your business name and your logo — on A4 or US Letter. Never our logo.
- **Feet, inches and sixty-fourths** — A tape calculator that does arithmetic the way the job is measured: feet-inch-fraction down to 1/64, added and subtracted without converting anything into decimals first.

## Price

**$19.99 once** — All thirteen calculators, the branded PDF quote export and saved quotes. One payment, no renewal, nothing that lapses.

Free keeps four calculators — the feet-inch-fraction tape, the unit converter, squaring and diagonals, and areas with paint — unlimited, with no ads and no watermark.

_No subscription. No ads. Your logo on the quote, never ours._

## What is in the app?

Thirteen calculators, chosen and then closed. The list stopped growing on purpose: across the review study behind this project, "simple" is the single most-praised attribute in the construction-calculator category, and every app that answered a feature request with another tab paid for it in its own reviews.

Four are free and unlimited. The other nine come with the one-time unlock, along with the quote export and saved quotes.

- Tape calculator — feet-inch-fraction math to 1/64 inch (free)
- Unit converter — imperial and metric (free)
- Squaring and diagonal — 3-4-5 checks and exact diagonals (free)
- Areas and paint — summed shapes, openings subtracted, paint quantity (free)
- Common rafter — rise, run, pitch and length with overhang
- Stairs — risers and treads from the total rise, checked against code limits
- Concrete — slab volume in yards and the number of bags to buy
- Gravel and soil — cubic yards, and the tonnage that appears on the ticket
- Drywall — sheets, screws, compound and tape
- Wall studs — stud count on-center plus plate stock
- Blocks and bricks — CMU and modular brick counts
- Board feet — lumber volume and cost
- Tile — counts with waste, for straight or diagonal lays

## Why pay-once, and what people did when it went away

The reason this app is priced the way it is came out of the data rather than out of a preference. Construction Master Pro is the app this category was built around, and when it moved to a subscription its reviews turned. In the Tenon Tools Phase 0 study, 280 of that app's 604 critical reviews mention subscription or pricing — out of 2,123 reviews collected for it in total.

The interesting part is not the anger, it is where those users went. When a reviewer named what they would use instead, the answer was overwhelmingly not another app: the physical Calculated Industries calculator drew 29 mentions, and BuildCalc, the only rival app that registered at all, drew 9. Thirty-eight named alternatives in total, and three quarters of them were a piece of hardware you buy once and keep in a toolbox.

That is the thing to compete with, and it sets a clear bar. A device with no subscription, no ads and no server behind it, that keeps working when the phone has no signal and does not stop working because someone stopped paying. Tenon Calc matches those terms and adds the two things a handheld calculator cannot do: it remembers what you did, and it prints a quote with your name on it.

One disclosure. Tenon Calc has not been released and has no reviews, no ratings and no users. Comparing our quality to a shipped product's would be dishonest in our favour, so the comparison above is about published terms only — what a thing costs, whether it renews, and whether it needs a connection. Those are commitments; quality is not a claim we have earned yet.

## From calculation to signed quote

The gap this fills shows up in the reviews as a request rather than a complaint. Across the construction-calculator category, quote, PDF and estimate output draws 201 mentions — 2.14% of the category's 9,373 critical reviews, spread over six apps. People are not asking for a better calculator. They are asking the calculator to hand them something they can send.

In Tenon Calc, any result can be added to the current quote as a line item. You set the quantity, the unit and the price, the subtotal and tax are computed, and the whole thing exports as a PDF sized for A4 or US Letter with your business name, your client's name and your logo at the top. Quotes are saved, so last month's job is still there when the client calls back.

The logo on that page is yours. There is no watermark, no "created with" line and no version of the export that advertises us — in the free tier or the paid one.

## How is the arithmetic checked?

A calculator that is wrong is worse than no calculator, because it is wrong with authority. Every calculator here is backed by test vectors: fixed inputs with known-correct outputs, checked against published worked examples from a second independent source, and run on every build. The release bar is at least 40 vectors per calculator, all passing, before version 1.0 ships.

This is not a marketing line borrowed from nowhere. In the same review study, wrong-results complaints are 16.7% of critical reviews on the German storefront — 34 out of 204 — against 1.0% on the US storefront, 96 out of 9,169. Whatever is causing that gap, an app that wants to be trusted in both places has to be able to show its work, so the calculators on this website state their formulas and walk a verified example for exactly the same reason.

Results are still planning figures. Bag yields differ by manufacturer, waste factors are a judgement call, and anything structural is governed by local code. The app says so where it matters, and so does this page.

## Offline, and what that actually means

Every calculation, every saved quote and every PDF export happens on the device. There is no account to create, nothing to log into, no sync and no server holding your work. A basement with no signal is the normal case here, not the degraded one.

The practical consequence is that nothing about the app can be switched off remotely, and nothing stops working because a service was retired. The app you buy is on your phone, and the quotes you made are files on it.

## The free tier, and what the unlock buys

The free tier is a working calculator rather than a trial. The feet-inch-fraction tape, the unit converter, squaring and diagonals, and areas with paint — unlimited, permanent, no ads anywhere in the app, nothing watermarked. For a lot of people that is the whole job.

The unlock is $19.99, or 19,99 € in the euro zone, paid once. It adds the other nine calculators, the branded PDF quote export and saved quotes. There is no monthly option, no annual option and no consumable to buy. The purchase is handled by the App Store or Google Play, so Tenon Tools never sees a card number, and the standard store restore flow moves it to a new device.

| What you get | Free | $19.99 once |
| --- | --- | --- |
| Calculators | Four | All thirteen |
| Feet-inch-fraction tape | Yes | Yes |
| Unit converter | Yes | Yes |
| Squaring and diagonals | Yes | Yes |
| Areas with paint | Yes | Yes |
| Branded PDF quote export | No | Yes |
| Saved quotes | No | Yes |
| Your logo on the quote | No export in this tier | Yours, never ours |
| Ads | None | None |
| Subscription | None | None |
| Watermark from us | None | None |
| Works offline | Yes | Yes |
| Account required | No | No |

_Tenon Calc free tier against the one-time unlock. Every row is a commitment made before release, not a measured result — the app has not shipped and has no reviews, ratings or users._

## FAQ

### Is there a subscription?

No, and there will not be one in this version. The free tier is four calculators with no ads and no expiry. The paid tier is a single payment of $19.99, or 19,99 €, for everything else. There is no monthly plan, no annual plan and no ad-supported tier. That is the whole price list.

### Does it work without a connection?

Yes, entirely. Calculations, saved quotes and the PDF export all run on the device with no network at all. There is no account, so there is nothing to sign into before you can use it, and no service that can go down and take the app with it.

### Whose logo goes on the PDF quote?

Yours. You set your business name and drop in your own logo, and that is what the client receives, on A4 or US Letter. Tenon Tools does not appear on the document in either tier, and there is no watermarked version of the export.

### What does the app do about metric and imperial?

One of the four free calculators is a dedicated imperial-to-metric converter, and the tape calculator works in feet, inches and fractions down to 1/64. How each of the other calculators presents its results is being settled before release and will be described here before launch — the app has not shipped, and we would rather leave the line blank than promise something you would only discover afterwards.

### What happens if I find a calculation that is wrong?

Send it to us with the inputs and the answer you expected. Reports that hold up become permanent test vectors, so the same error cannot return in a later build — that is the mechanism, not a promise of goodwill. The support page explains what to include.

---

_Tenon Calc is unreleased and has no reviews of its own. Review figures on this page are computed counts from the Tenon Tools Phase 0 study of 208,539 in-scope app-store reviews collected in August 2026; construction-calculator shares use that category's 9,373 critical reviews as the denominator, and the German and US accuracy figures use their own storefront critical-review counts. Calculator results are planning figures — verify materials against your supplier and anything structural against your local code._

Page: https://tenon.tools/calc/ — this file is its markdown mirror. All mirrors: https://tenon.tools/llms.txt