Workbench
Machinist Calculator
A scientific calculator with shop defaults: trig in degrees, DMS angles (30°15′36″) in and out, a nearest-1/64 fraction line under every answer, one-tap in⇄mm and a tape that survives reloads. Type with the keyboard or the keys below.
Built for the shop, not the classroom
Generic scientific calculators make you pay a small tax on every shop calculation: radians by default, no fractions, no DMS, no unit sense. This one starts where machinists work — degrees-first trig for sine bars, dovetails and bolt circles; print-style 30°15′36″ angles entered directly with the ° ′ ″ keys; a 1/64 fraction line under every answer with the residual spelled out; and in⇄mm conversion of whatever is on the display, because half of every print is in the other unit system.
The expression line evaluates with real precedence (−3² = −9, 2π and 2(1+3) just work), trailing parentheses close themselves, EE enters powers of ten, and the tape keeps the last dozen results one tap from reuse — including after a reload.
When a dedicated tool is better
Arithmetic is half the job — the other half is knowing the formula and its limits. For those, the dedicated tools carry the engineering context: speeds & feeds, SFM⇄RPM, tap drills, thread limits, chip thinning, arc from chord & rise and the rest of the machining cluster — 370+ calculators, each with its formula, worked example and limits stated.
FAQ
What makes this a machinist calculator instead of a generic scientific calculator?
Shop defaults: trig works in degrees out of the box, angles enter and read back as degree-minute-second (30°15′36″), every result shows a nearest-1/64 fraction with the residual, one tap converts the answer between inches and millimeters, and the tape keeps your last dozen calculations across page reloads.
How do I enter a degrees-minutes-seconds angle?
Chain the unit keys: 30 ° 15 ′ 36 ″ evaluates to 30.26 decimal degrees, and works inside functions — sin(30°15′ gives the sine of 30.25°. Non-integer results also show a ∠ readout converting decimal degrees back to DMS. On the keyboard, D ′ and ″ (apostrophe and quote) type the markers.
How do I calculate a sine bar stack with it?
Type 5 × sin(30 and press equals: gauge stack = bar length × sin(angle), so a 5 in bar set to 30° needs a 2.5 in stack. For a print angle of 16°36′, type 5 × sin(16°36′ directly — no decimal conversion needed.
Does it convert decimals to fractions?
Every result automatically shows the nearest 1/64 fraction and how far off it sits — 0.7376 reads as 47/64 in + 0.0032. The fraction line is exact when the result lands on a 64th.
Can I use the keyboard?
Yes — digits, + − * / ^ ( ) % and the decimal point type directly, Enter evaluates, Backspace deletes the last entry (whole functions delete in one stroke), Escape clears, A inserts the previous answer, and D ′ ″ enter DMS angle markers.
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