LogicCommons Beta release
Engineering , 17 calculators

Home Projects Engineering Calculators

Check panel capacity, size a generator or an EV charger circuit, and plan gutters, French drains, sump pumps and rainwater tanks for a house. Room heat loads, ventilation, wall R-values and window comparisons cover comfort and energy.

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Does my panel have room for another circuit?Circuit Load Panel Capacity Calculator Will this generator carry my loads, motor starts included?Generator Sizing Calculator What circuit does an EV charger need, and how long will charging take?EV Charger Circuit Planner Calculator How big should my gutters and downspouts be?Gutter Downspout Sizing Calculator Which sump pump keeps up with my discharge line?Sump Pump Sizing Calculator How big a heater or air conditioner does this room need?Room Heat Load Heater AC Sizer Calculator
The calculators

All 17 home projects engineering calculators

Home envelope & comfort

Assembly R Value Whole Wall Calculator

Builds two transparent parallel heat-flow paths from a complete layer schedule, reports cavity, framing, and whole-wall thermal resistance, and optionally screens a degree-day retrofit payback.

 Home electrical & energy

Circuit Load Panel Capacity Calculator

Builds a fixed split-phase circuit schedule, separates continuous and noncontinuous current, applies a transparent 125 percent planning multiplier, routes each load to the correct panel leg, and reports the binding spare-capacity result. It can also take the existing load as a dwelling's calculated service load by the standard method, from its floor area, circuits and appliances, and then gives the load current and the next standard service size.

 Home envelope & comfort

Condensation Dew Point Risk Calculator

Calculates interior and exterior dew points with the Magnus relation, maps a steady-state temperature gradient through a complete assembly, and identifies the evaluated interface with the smallest dew-point margin.

 Home electrical & energy

EV Charger Circuit Planner Calculator

Routes EVSE current from nameplate, restricted commissioning, or desired AC power; separates branch sizing from listed load-management allocation; derives conductor resistance from AWG geometry; checks voltage drop and panel legs; and estimates charging time with an optional high-SOC taper segment.

 Home water & drainage

French Drain Yard Drainage Calculator

Routes Rational or direct inflow through eight full-pipe Manning candidates and exposes capacity, velocity, trench, gravel, and cost trade-offs.

 Home electrical & energy

Generator Sizing Calculator

Computes real and apparent running load, unrolls six motor-start groups, compares manual, priority-shed, automatic, and listed-EMS routes, checks split-phase leg loading and a site-derated generator candidate, and interpolates an editable manufacturer fuel curve.

 Home water & drainage

Gutter Downspout Sizing Calculator

Routes direct or sectioned roof area through Rational runoff, Manning gutter capacity, and independent outlet-capacity and spacing counts.

 Home water & drainage

Irrigation Zone Designer Calculator

Combines eight irrigation groups into a simultaneous zone and audits flow, Hazen losses, pressure margins, precipitation matching, target depth, and cycle-and-soak schedule.

 Home electrical & energy

Long Run Voltage Drop Calculator

Derives AWG cross-section and temperature-adjusted conductor resistance, evaluates single-phase, balanced three-phase, or DC runs, and computes every editable conductor candidate against ampacity, running-drop, starting-drop, and cost criteria.

 Home water & drainage

Rainwater Harvesting Tank Sizer Calculator

Runs a twelve-month storage balance across one entered tank or a fixed 21-capacity ladder and exposes reliability, overflow, reserve, and simple economics.

 Home envelope & comfort

Room Heat Load Heater AC Sizer Calculator

Builds a room-level steady-state heating and cooling load from envelope UA, outdoor airflow, solar, sensible, and latent gains, then screens user-entered equipment candidates against the active capacity targets.

 Home electrical & energy

Solar Battery Starter Sizing Calculator

Screens annual-energy, backup-with-recharge, or combined solar-plus-storage requirements against eight editable packages and exposes energy flow, power gates, first-year value, and discounted payback.

 Home water & drainage

Sump Pump Sizing Calculator

Intersects eight auditable generic pump curves with a routed discharge-system curve, then screens flow reserve, velocity, and optional cycling.

 Home envelope & comfort

Ventilation Fresh Air Calculator

Calculates a whole-dwelling outdoor-air target from editable area and room rates, an entered target, or a CO2 mass balance, then checks installed airflow and a complete local-exhaust schedule.

 Home water & drainage

Water Hammer Surge Estimator Calculator

Screens eight valve or pump events with routed velocity, elastic or entered wave speed, critical closure time, and Joukowsky pressure change.

 Home electrical & energy

Whole Home Electrification Load Calculator

Compares connected-load, separated-new-load, and metered maximum-demand routes for a before-and-after home electrification project while preserving an auditable twelve-row appliance and equipment inventory.

 Home envelope & comfort

Window Heat Gain Loss Comparator Calculator

Compares user-entered window U-factors, solar-gain coefficients, and installed costs across heating, cooling, or combined scopes, then selects by annual energy cost, positive payback, or peak load.
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