Calculations in Number Fields

Calculations in number fields

Any number box in Gubbins can do quick maths for you. Instead of reaching for a calculator, type the sum straight into the field — 500/2 — and Gubbins works out the value (250) when you press Enter or click away.

Where to find it: every numeric field — quantities, unit costs, capacities, weights, reorder points, warranty windows, and the rest.

How it works

1. Click into a number field and type a calculation, e.g. 24/2 or 12*3.
2. A small preview appears at the edge of the field showing the running result (= 12).
3. Press Enter, or simply click/tab away, and the field settles to the answer.

If what you typed isn't a valid sum, the field is left exactly as you typed it — nothing is guessed or thrown away — so you can fix it and try again.

What you can type

You type	You get	Notes
500/2	250	Divide
12*3	36	Multiply (× works too)
40+8	48	Add
50-6	44	Subtract (− works too)
(2+3)*4	20	Parentheses set the order
200*15%	30	% means "divide by 100", so this is 15% of 200
2^10	1024	^ raises to a power

Spaces are ignored, so 500 / 2 is fine. Ordinary priority applies — 2+3*4 is 14, not 20.

💡 Tip This is perfect for splitting a pack (kg you bought ÷ number of items), scaling a recipe or a bill of materials, or working out a percentage discount without leaving the field.

ℹ️ Note The calculator only ever changes the single field you typed into. It's a convenience for entering a value, not a formula that stays linked to anything — the field just holds the number you worked out.

Accessibility

The feature is built to be usable by everyone:

• Each number field tells assistive technology that it accepts calculations, so the help is never hidden behind a hover.
• The worked-out result is announced when the field settles, so you don't have to see the preview to know what it became.
• Everything works from the keyboard — type the sum and press Enter.

Related pages

• Items — where you'll enter quantities, costs and capacities.
• Locations & stock — capacities and on-hand counts.
• Low stock & gauges — reorder points and thresholds.
• Command palette & shortcuts — more keyboard-first conveniences.