# Radiator Calculator Pro

> Heat Output & BTU Calculator

Canonical page: [https://chrome-stats.com/d/id6743349772](https://chrome-stats.com/d/id6743349772)

## Overview

- **ID:** `id6743349772`
- **Platform:** Apple
- **Type:** Apple app
- **Status:** Available
- **Publisher:** DigitalKind Ltd
- **Category:** Utilities
- **Version:** 1.5
- **Last updated:** 2026-05-15
- **First published:** 2025-03-17
- **Size:** 15 MB
- **Data as of:** 2026-09-18
- **Store listing:** [Apple App Store](https://apps.apple.com/us/app/radiator-calculator-pro/id6743349772)
- **Website:** [https://digitalkind.io/](https://digitalkind.io/)
- **Privacy policy:** [https://www.freeprivacypolicy.com/live/19d391e3-1a43-4433-932b-ee6b7e041ec8](https://www.freeprivacypolicy.com/live/19d391e3-1a43-4433-932b-ee6b7e041ec8)

## Description

Room-by-room radiator sizing with ΔT correction for heat pumps. Watts, BTU/h, metric or imperial. Free for one room; PRO unlocks unlimited rooms.

Room-by-room radiator sizing. Watts and BTU/h output for any room, factoring volume, glazing, external walls, roof and floor exposure, and insulation standard.

Calculation
Heat output per room with adjustments for:
• Room type (8 presets: bedroom, living room, bathroom, kitchen, hallway, office, conservatory, garage)
• Internal volume
• Window-to-floor ratio
• Number of external walls (0–4)
• What's above (loft, pitched roof, flat roof, heated space)
• What's below (garage, unheated cellar, uninsulated floor, heated floor)
• Insulation level: poor (older single-glazed) → average (modern build) → good → excellent (new-build, triple-glazed)
• Mean water temperature - ΔT30, ΔT35, ΔT40, ΔT50, ΔT60

ΔT correction uses the standard panel-radiator exponent (n = 1.30) per EN 442 testing convention. A 5% safety margin is applied to avoid undersizing.

Heat-pump systems

Select ΔT35 or ΔT30 to spec radiators for low-temperature systems. Output is rescaled — a 1000W ΔT50-rated radiator delivers ~630W at ΔT35 — so you size to actual delivered heat, not nameplate.

Output
• Watts and BTU/h side-by-side
• Metric or imperial dimensions
• Whole-home heat-loss total
• Share or export room specs as text

For plumbers, heating engineers, and heat-pump installers sizing radiator schedules, and homeowners or landlords running their own jobs.

## Rankings

- #2,256,664 — Overall

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Source: [Chrome-Stats](https://chrome-stats.com/d/id6743349772)