calctricA toolkit you can take with you.
Calctric is an independently developed app for everyday trade calculations. Its tools cover measurements, electrical calculations, conduit bending and keeping work organized. The website gives you a selection of free browser calculators and practical guides to the tools inside the app.
The app has a free version. Premium is an optional one-time purchase for additional capabilities, including full voltage-drop workflows, advanced bends and supported CEC tools. The tool directory identifies each tool’s access and scope.
The web calculators work without signup. They do not synchronize with the app. See the privacy policy for how browser calculations, app data and support messages are handled.
METHODS REVIEW · OCTOBER 10, 2026
Shared rules. Checked examples.
The browser calculators are based on the corresponding Calctric app calculation methods. Checks include known examples, unit conversions, invalid inputs and comparisons between browser and app results.
For this version, 204 reference outputs generated from the app’s calculation code were compared with the web versions of conversions, Usage & Cost, the K-factor voltage estimate and finished offset layouts. The measurement calculator has separate checks for fractions, mixed units, operation order and rounding.
These are software checks, not independent certification or field calibration. A matching calculation can still be unsuitable when a measurement, equipment assumption or installation condition is wrong. Review the method below and verify the conditions that matter to your job.
Feet, inches & fractions.
Length entries are converted to inches internally. Operations run in entry order, from left to right. Selecting a result unit changes how the answer is displayed; it does not round the stored result for subsequent arithmetic.
The tape readout rounds to the nearest 1/16 inch. At an exact half-sixteenth tie, rounding is away from zero. The precision of a displayed fraction does not establish the accuracy of your original measurement.
Conduit offset geometry.
The model joins two equal, opposite circular bends with a straight section. It uses centreline rise, bend angle, actual conduit outside diameter, centreline bend radius and finished horizontal length. The starting pipe length includes the geometric shrink.
What is calculated?
For rise h, radius R and bend angle θ, the straight between the bends is [h − 2R(1 − cos θ)] ÷ sin θ. The horizontal offset run is 2R sin θ plus that straight multiplied by cos θ. Developed offset length is 2Rθ plus the straight, with θ in radians. Geometric shrink is developed length minus horizontal run.
The remaining finished length is divided between the first and final straights according to your placement choice. Bend-centre marks are arc midpoints measured along the unbent pipe. Nominal arrow marks use each arc’s start station + R + outside diameter ÷ 2 − the entered 90° deduct.
Arrow placement is a circular-arc inference, not a measured calibration of a particular shoe. A centre mark must match the chosen angle’s reference. Check the actual equipment, grip length, seating, springback and a test piece. Fitting engagement and trimming allowances are separate.
The guide describes the app’s hook-toward-START hand-bender sequence. It is not a replacement for your bender’s operating instructions. A manufacturer’s hand-bender guide illustrates why references and operating methods must match the equipment; its table method should not be mixed with this model’s marks.
Unit conversions.
Length and area use international-foot and SI definitions: 1 ft = 0.3048 m and 1 in = 25.4 mm exactly. Area uses squared length factors. Temperature conversions include scale offsets and reject values below absolute zero.
Mechanical horsepower and metric horsepower have different factors. Energy and BTU conversions use International Table definitions. kW ↔ kVA requires your power factor and does not apply a motor-efficiency assumption.
Definitions follow the same factors used in the app and the NIST Guide to the SI conversion factors. Display rounding is separate from the conversion. Swap carries up to 15 significant digits.
Usage & cost.
Daily energy in kWh equals electrical input power in kW per item × quantity × average hours per day. Multiply energy by your entered price per kWh for the energy cost.
Weekly totals use 7 days; monthly totals use your chosen month length; yearly totals use 365 days. Comparison savings are the baseline minus each alternative under the entered assumptions. A percentage is not calculated against a zero-energy baseline.
An empty tariff gives energy only; a zero tariff gives zero cost. Currency is a label, not an exchange-rate conversion. Fixed charges, taxes, changing tariffs, demand charges and equipment purchase costs are excluded. Use average runtime for cycling equipment.
Basic voltage-drop estimate.
The free browser tool implements the app’s K-factor estimate for one conductor set. Voltage drop = circuit factor × K × current × one-way length in feet ÷ conductor area in circular mils. K is 12.9 for copper or 21.2 for aluminum. The factor is 2 for two-wire AC/DC or √3 for balanced three-phase.
This resistance-only estimate does not model conductor temperature, reactance, power factor, raceway effects, upstream drop or connections. It displays drop in volts and percent, plus estimated load voltage, to two decimal places. The underlying calculation keeps its precision.
The browser estimate uses no CEC or NEC code tables. It does not check ampacity or approve a conductor size. The app’s Premium Voltage Drop tool provides the supported CEC 2024 and NEC workflows. Check the method, region and locally adopted requirements for your installation.
Help us improve the tools.
If an answer looks wrong, tell us the tool, inputs, units, selected settings, result and what you expected. A source or worked example helps us reproduce the issue. Share only information you are comfortable sending.
Calctric is independent of code publishers and equipment manufacturers. Results are calculation aids and may contain errors. Read the terms and safety disclaimer before relying on them.