What is the YUNZII C21 Numpad Calculator?

It’s a compact 18-key mechanical numpad with a built-in calculator mode, a small TFT screen, and three operating modes: keyboard, calculator, and gaming. You can use it as a number pad alongside a full-size keyboard or as a standalone desk accessory.

How can I connect the C21 to a computer?

The C21 supports three connection options: Bluetooth, 2.4 GHz wireless, and wired USB-C. This lets you choose a wireless setup or connect it by cable.

Can I use this numpad with both Windows and macOS?

Yes. The C21 supports Windows and macOS customization software, as well as online customization. Its compact keypad can also be useful when a laptop or compact keyboard doesn’t have a dedicated number pad.

What does calculator mode do?

Calculator mode lets you use the C21 as a dedicated calculator rather than only sending keystrokes to a computer. The TFT screen provides a display area, while the mode options make it possible to switch between calculator and keyboard use.

Can I change the switches on the YUNZII C21?

Yes. All keys are hot-swappable, and the sockets support compatible 3-pin and 5-pin mechanical switches. The C21 is offered with YUNZII Candy linear or YUNZII Sage linear switches.

What are the keycaps like?

The C21 uses dye-sublimated PBT keycaps in an MOA profile. PBT is a commonly used keycap material, and the MOA shape gives the keys a distinctive rounded look.

Does the C21 have customizable lighting?

It has south-facing RGB lighting beneath the keys, along with side lighting. These lighting zones add illumination around the compact keypad.

Is it suitable for gaming or other custom key assignments?

The C21 includes a gaming mode and supports customization through its software or online tool. Its full N-key rollover feature is designed to register multiple key presses at the same time.

How much space does this numpad take up?

It measures about 98.3 × 152.56 × 38.9 mm, so it has a small footprint compared with a full keyboard. Its 18-key layout keeps number-pad functions close at hand without taking up much desk space.

What is the battery capacity, and how long does it last?

The C21 has a 2500 mAh battery. Actual battery life can vary with use and settings; the listed capacity alone doesn’t specify a runtime.

Can I use the C21 while it is connected by cable?

Yes. It supports a wired connection through USB-C in addition to Bluetooth and 2.4 GHz wireless modes.

What color and switch options are available for the C21?

The listed case color choices are pink, beige, purple, and coffee. Switch choices include YUNZII Candy linear and YUNZII Sage linear switches.

Yunzii C21 Starting at $53.99

Name: Yunzii C21
Brand: Yunzii
SKU: yunzii-c21-wireless-mechanical-numpad-keyboard-calculator

Vendor	Location	Coupon Code	In Stock	Price (USD)	Link*
Yunzii C21
	Global	-	Check vendor	Check vendor	Visit shop
YUNZII C21 Wireless Mechanical Numpad Keyboard & Calculator
	Shipping to US			$54	Visit Shop

Vendor

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Price (USD)

Link*

Yunzii C21

Global

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YUNZII C21 Wireless Mechanical Numpad Keyboard & Calculator

Yunzii C21 - Pink / YUNZII Candy Linear Switch

Shipping to US

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Compare Yunzii C21 vs KBDFans MM HE M64 vs Womier SK30 Kanagawa Numpad Specification

Compare similar keyboards side by side, or use the comparison table to compare all keyboards!

Model	Yunzii C21	KBDFans MM HE M64	Womier SK30 Kanagawa Numpad
	65	61	76
Rating	0.0 stars (0 reviews)	0.0 stars (0 reviews)	0.0 stars (0 reviews)
Purchase Options
Main differences	Equipped with a 2500 mAh battery Weighs about 250 g Sized at 39 x 153 x 98 mm	Released in 2025 Has Magnetic switch options Includes a No display Utilizes Hall effect sensors Enables rapid trigger functionality Includes screw-in stabilizers Has built-in sound dampening Supports Wired, Wired only connectivity Runs at a 8000 Hz polling rate Offers Yes, Rgb RGB lighting	Comes with a knob Equipped with a 3000 mAh battery Made with a ABS case
Score	Scores Performance: 69.6 Build Quality: 62.6 Productivity: 58.3 Customizability: 66.4 Portability: 88	Scores Performance: 91.2 Build Quality: 54.3 Productivity: 56 Customizability: 58.8 Portability: 59.4	Scores Performance: 74.9 Build Quality: 71.7 Productivity: 76.2 Customizability: 79.5 Portability: 90.2
Name	Name Yunzii C21	Name KBDFans MM HE M64	Name Womier SK30 Kanagawa Numpad
Release year	Release year 2026	Release year 2025	Release year 2026
Switch Options	Switch Options Linear	Switch Options Magnetic	Switch Options Linear
Profile	Profile Normal Profile	Profile Normal Profile	Profile Normal Profile
Hot Swappable	Hot Swappable	Hot Swappable	Hot Swappable
Layout Size	Layout Size Numpad	Layout Size Numpad	Layout Size Numpad
Layout Standard	Layout Standard -	Layout Standard ANSI	Layout Standard ANSI
Layout Ergonomics	Layout Ergonomics Normal	Layout Ergonomics Normal	Layout Ergonomics Normal
Knob Support	Knob Support	Knob Support	Knob Support
Display Support	Display Support TFT	Display Support	Display Support TFT
Mac/Win Support	Mac/Win Support	Mac/Win Support	Mac/Win Support
Multi-Media Keys	Multi-Media Keys	Multi-Media Keys	Multi-Media Keys
USB-C	USB-C	USB-C	USB-C
USB passthrough	USB passthrough	USB passthrough	USB passthrough
Connection	Connection Bluetooth, 2.4 GHz, Wired, Wireless	Connection Wired, Wired only	Connection Bluetooth, 2.4 GHz, Wired, Wireless
Polling Rate	Polling Rate 1000 Hz	Polling Rate 8000 Hz	Polling Rate 1000 Hz
Battery capacity	Battery capacity 2500 mAh	Battery capacity -	Battery capacity 3000 mAh
Hall Effect Support	Hall Effect Support	Hall Effect Support	Hall Effect Support
QMK Support	QMK Support	QMK Support	QMK Support
VIA Support	VIA Support	VIA Support	VIA Support
VIAL Support	VIAL Support	VIAL Support	VIAL Support
N-Key Rollover	N-Key Rollover	N-Key Rollover	N-Key Rollover
Rapid Trigger	Rapid Trigger	Rapid Trigger	Rapid Trigger
Mount Style	Mount Style Gasket Mount	Mount Style -	Mount Style Gasket Mount
Screw in Stabilizers	Screw in Stabilizers	Screw in Stabilizers	Screw in Stabilizers
Sound Dampening	Sound Dampening	Sound Dampening	Sound Dampening
Backlight	Backlight Rgb, South-face	Backlight Rgb	Backlight Rgb, South-face
Case Colors	Case Colors	Case Colors	Case Colors
Case Material	Case Material -	Case Material -	Case Material ABS
Keycaps Material	Keycaps Material PBT	Keycaps Material -	Keycaps Material PBT
Dimensions	Dimensions 39 x 153 x 98 mm	Dimensions -	Dimensions -
Weight	Weight 250g	Weight -	Weight -

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Product Description

The Yunzii C21 is a compact wireless numpad that can also operate as a calculator or gaming keypad. It suits users who want a separate number-entry pad with switch customization and a small display, but it is not a replacement for a full-size keyboard.

Features and flexibility

Switch between keyboard, calculator, and gaming modes for different tasks. The TFT screen provides a small visual display, while RGB lighting offers some desk-side customization. Hot-swappable sockets let you change switches without soldering, and the included linear switch options provide a choice of switch feel.

Typing and setup

The gasket mount uses a cushioned layer between parts of the keyboard structure, which can soften the typing feel. Dye-sublimated PBT keycaps are designed for durable legends. Software and online customization support Windows and macOS, giving users ways to adjust the setup for their workflows.

Connectivity and trade-offs

Bluetooth, 2.4 GHz wireless, and USB-C wired connections give you options for different devices and desk setups. The compact key count is useful when space matters, but limits its role to number entry and assigned keypad functions. Battery life is Unknown, so wireless runtime cannot be judged from the available information.

Good fit: users who want a configurable numpad with calculator functionality and multiple connection modes.
Less ideal: anyone needing a complete keyboard or a conventional full-size calculator keypad.

Frequently Asked Questions (FAQ)