That calculator works for other thermistors, because I've used it before. I'd say make sure the values in the config are close to what the calculator came up with (HeaterMeter didn't misinterpret them so like 1.428e-06 didn't become just 1.428). There will be some loss of precision due to how floats are stored in RAM, but they should round to having at least 3 significant digits accurate. Also be sure to keep your "Resist" to 10000 in the config because that's the fixed resistor that's installed in HeaterMeter, not the resist of the probe / ambient thermistor.
EDIT: I should say also be sure you use the calculator in Celsius.