---
product_id: 667423726
title: "Concise Ruler Circular Calculator 27N 100805"
brand: "concise"
price: "S/.171"
currency: PEN
in_stock: true
reviews_count: 12
category: "Concise"
url: https://www.desertcart.pe/products/667423726-concise-ruler-circular-calculator-27n-100805
store_origin: PE
region: Peru
---

# 3.3-inch diameter precision scale Accurate 3-digit calculation capability Multi-functional calculation & conversion Concise Ruler Circular Calculator 27N 100805

**Brand:** concise
**Price:** S/.171
**Availability:** ✅ In Stock

## Summary

> 🧮 Master calculations the vintage way — precision meets style!

## Quick Answers

- **What is this?** Concise Ruler Circular Calculator 27N 100805 by concise
- **How much does it cost?** S/.171 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.pe](https://www.desertcart.pe/products/667423726-concise-ruler-circular-calculator-27n-100805)

## Best For

- concise enthusiasts

## Why This Product

- Trusted concise brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **User-Friendly Design:** High-contrast, easy-to-read scales paired with a dedicated storage case and clear instructions for seamless use.
- • **Timeless Analog Reliability:** Experience the classic slide rule accuracy that outperforms digital calculators in tactile engagement and focus.
- • **Versatile Calculation Modes:** Effortlessly handle multiplication, division, squares, cubes, and proportional ratios all in one tool.
- • **Compact Precision Powerhouse:** A sleek 3.3-inch diameter vinyl scale delivering precise calculations with ease.
- • **Comprehensive Unit Conversion:** Instantly convert length, area, volume, mass, temperature, pressure, and speed without switching devices.

## Overview

The Concise Ruler Circular Calculator 27N 100805 is a compact, 3.3-inch diameter vinyl circular slide rule designed for professionals who value precision and versatility. It supports multiplication, division, squares, cubes, and proportional calculations, alongside a reverse side featuring multiple unit conversions. Lightweight and portable, it includes a storage case and manual, making it an essential analog tool for engineers, architects, and managers seeking reliable, distraction-free calculation.

## Description

This is the most popular circular calculation scale, which is not added, subtracted... It is a basic calculation scale that can easily calculate multiplication, division, square, and triple, and is used in all fields. Calculation type: General exclusion, proportional (exponent hundred ratio), square and cu. Reverse side: Length and area, volume, mass, temperature, pressure, speed, etc. are listed for unit conversion Scale: D, C, CI, A, K (surface) Dedicated storage case, instruction manual included.

Review: The Industry Standard - The quality of this slide rule is quite nice and it is easily readable. The contrast on the font is quite comfortable to read. I had never used a slide rule before, but the instructions are quite clear and I found it to be accurate and easier to use than I had originally thought it would be. It's kind of fun to use. I highly recommend this product.
Review: Decent slide rule at a decent price. Well made. - This is a relatively standard circular slide roll with the most important scales being c and d on the front and of course the trig functions on the obverse. Everything works. I noted that there were some comments that said it wasn't precise enough. It seems fine to me. I can do three digits for most calculations, whereas for the borderline ones some of them are like 2.5 digits. Everything works fine. It's in good condition and I'm glad somebody still makes real slider rules. If you're not familiar with this particular format. This is roughly equivalent to a 12-in slide rule. The outer scales are a little bit longer and therefore a tiny bit more precise than a 12-in and the inner scales are roughly equivalent to an 8-in wide rule. That of course is because the diameter is what determines the precision. And the diameter changes depending on whether using inner scale or outer scales.

## Features

- Size: Diameter: Approx. 3.3 inches (84 mm)
- Main Material: Vinyl chloride

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B01GPV0Z4I |
| Best Sellers Rank | #244,304 in Office Products ( See Top 100 in Office Products ) #29 in Triangular Scales #933 in Drafting Tools & Drafting Kits |
| Date First Available | June 28, 2016 |
| Is Discontinued By Manufacturer | No |
| Item Weight | 0.563 ounces |
| Item model number | 100805 |
| Manufacturer | コンサイス(Concise) |
| Product Dimensions | 3.3 x 3.3 x 0.04 inches |

## Product Details

- **Brand:** CONCISE
- **Color:** Black
- **Graduation Range:** 3.3 Inches
- **Material:** Polyvinyl Chloride (PVC)
- **Style:** 27N

## Images

![Concise Ruler Circular Calculator 27N 100805 - Image 1](https://m.media-amazon.com/images/I/81ksn7IVHcL.jpg)

## Customer Reviews

### ⭐⭐⭐⭐⭐ The Industry Standard
*by T***H on October 21, 2025*

The quality of this slide rule is quite nice and it is easily readable. The contrast on the font is quite comfortable to read. I had never used a slide rule before, but the instructions are quite clear and I found it to be accurate and easier to use than I had originally thought it would be. It's kind of fun to use. I highly recommend this product.

### ⭐⭐⭐⭐⭐ Decent slide rule at a decent price. Well made.
*by B***Y on September 13, 2025*

This is a relatively standard circular slide roll with the most important scales being c and d on the front and of course the trig functions on the obverse. Everything works. I noted that there were some comments that said it wasn't precise enough. It seems fine to me. I can do three digits for most calculations, whereas for the borderline ones some of them are like 2.5 digits. Everything works fine. It's in good condition and I'm glad somebody still makes real slider rules. If you're not familiar with this particular format. This is roughly equivalent to a 12-in slide rule. The outer scales are a little bit longer and therefore a tiny bit more precise than a 12-in and the inner scales are roughly equivalent to an 8-in wide rule. That of course is because the diameter is what determines the precision. And the diameter changes depending on whether using inner scale or outer scales.

### ⭐⭐⭐⭐ Fun little devices. Both of them
*by A***R on May 10, 2025*

It's a nice little instrument, but doesn't have all of the functions of classic slide rules. It multiplies, divides, finds inverses, does square and cubes, square roots and cube roots, but does not do trig functions or logarithms. It has a handy set of conversion factors on the back side. It's somewhat of a novelty these days, since you can buy an electronic scientific calculator for less, but it would be fun to show to younger folks who never learned to use a slide rule. Made in Japan, but made for the western market, so instructions are in English. This review so far refers specifically to the model number 28n. Several models were shown on the same listing, and not all of them had instructions in English. I also purchased the one labelled No. 480, and the instructions that came with that one were in Japanese. Fortunately, the front side was very similar to a circular slide rule that I purchased in college and I was able to figure out how to use the front side based on those instructions. It did everything that the model 28n did, plus logarithms, but it still did not do trig functions. It has a larger diameter than the 28n, which makes it somewhat easier to read. The back side was a long term calendar from 1926 to 2043. It also shows the corresponding years of the three most recent Japanese eras (Showa, Heisei, and Reiwa). I was able to figure out a lot by observation, but, again, the instructions are in Japanese.

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*Product available on Desertcart Peru*
*Store origin: PE*
*Last updated: 2026-04-24*